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Sample records for biopsy clamp yields

  1. [Frameless stereotactic biopsy: diagnostic yield and complications].

    PubMed

    Castle, Maria; Nájera, Edinson; Samprón, Nicolas; Bollar, Alicia; Urreta, Iratxe; Urculo, Enrique

    2014-01-01

    The aim of this study was to evaluate the variables that could modify the diagnostic yield of frameless stereotactic biopsy, as well as its complications. This was a retrospective study of frameless stereotactic biopsies carried out between July 2008 and December 2011 at Donostia University Hospital. The variables studied were size, distance to the cortex, contrast uptake and location. A total of 70 patients were included (75 biopsies); 39 males and 31 females with an age range between 39 and 83 years. The total diagnostic yield in our series was 97.1%. For lesions >19mm, the technique offered a sensitivity of 95.2% (95% CI: 86.9-98.4) and specificity of 57.1% (95% CI: 25.0-84.2). The yield was lower for lesions within 17mm of the cortex: sensitivity of 74.6% (95% CI: 62.1-84.7) and specificity of 71.4% (95% CI: 29.0-96.3). Seven (10%) patients developed complications after the first biopsy and none after the second. The diagnostic yield was lower for lesions less than 2cm in size and located superficially. In this series we did not observe an increased rate of complications after a second biopsy. Copyright © 2013 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  2. Diagnostic Yield and Safety of Cerebellar and Brainstem Parenchymal Biopsy.

    PubMed

    Tobin, W Oliver; Meyer, Fredric B; Keegan, B Mark

    2015-12-01

    We aimed to determine the diagnostic yield and safety of posterior fossa parenchymal biopsy. One-hundred-thirty-six patients who underwent 137 posterior fossa (brainstem or cerebellar) parenchymal biopsies at Mayo Clinic (Rochester, Minnesota, USA) between 1996 and 2009 were identified by chart review. Case histories; radiologic, surgical, and pathologic reports; and safety outcomes were assessed. Posterior fossa parenchymal biopsies were performed on 78 male and 58 female patients of median age 47 years (interquartile range 28-61). Preoperative clinical diagnosis in the majority of cases was of a malignant neoplasm. Glial neoplasm (51%) was the most common finding followed by lymphoma (7%) and neurosarcoidosis (7%). Normal tissue or nonspecific changes were observed in 28 cases (20%). Three deaths occurred: 2 at the time of biopsy (1%) and 1 due to underlying disease. All deaths occurred in patients who had a cerebellar biopsy. Transient neurologic deficits occurred in 15 patients (11%): worsening of presenting symptoms (4), cardiac arrhythmia (3), vertigo (2), diplopia (2), ataxia (3), seizure (1), decreased consciousness (1), and limb numbness (3). Sustained neurologic deficits occurred in 3 patients: fourth nerve palsy (1), hemiparesis (1), and facial numbness (1). The diagnostic yield of posterior fossa parenchymal biopsy in Mayo Clinic patients with diverse pathologies was 80%. The complication rate was 11% with the majority being transient, but 2 deaths were attributed to biopsy. Evaluation of the diagnostic yield and complication rate at individual neurosurgical centers is needed to determine generalizability of these results. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. TRUS Biopsy Yield in Indian Population: A Retrospective Analysis

    PubMed Central

    Pawar, Prakash Wamanrao; Sawant, Ajit Somaji; Patil, Akshay Vijay; Narwade, Sayalee Suryabhan; Mundhe, Shankar Tanaji; Savalia, Abhishek Jaysukhbhai; Tamhankar, Ashwin Sunil

    2017-01-01

    Introduction The reported cancer detection rate of Trans-Rectal Ultrasonography (TRUS) biopsies (TRUS biopsy yield) has been around 30 percent in western countries. However it is much lower in Asian countries, including India. Hence a larger proportion of patients in India undergo unnecessary biopsies. Aims To find out the cancer detection rate of TRUS biopsy (TRUS biopsy yield) in contemporary Indian population. Also, to study the positive predictive values at different serum Prostate-Specific Antigen (PSA)/PSA Density (PSAD) cut off levels and suspicious Digital Rectal Examination (DRE) findings. Materials and Methods This retrospective study was carried out in a tertiary care institute. All symptomatic patients who underwent TRUS guided biopsy for indication of raised serum PSA level (>4 ng/ml) or suspicious DRE findings (nodule, irregularity, hard consistency, immobile rectal mucosa) from January 2012 to December 2014 were included. For serum PSA range (4-10) ng/ml, TRUS guided biopsy was done in patients with percent free/total PSA < 25. Statistical analysis used were Chi-square test, Mann-Whitney U-test, Spearman’s rank correlation analysis and Receiver-Operating Characteristic (ROC) curve. Results Out of the 235 patients included, 60 patients had malignancy (overall cancer detection rate= 25.53%). The cancer detection rate for PSA ranges of (4-10) and (10-20) ng/ml was as low as 5.95% and 13.16% respectively. Patients with malignant disease had significantly smaller prostate gland size than patients with benign disease (53.89 vs 63.06; p-value <0.05). On the other hand, cancer detection rate was 100% for PSA greater than 50ng/ml. The cancer detection rates were only upto 10% for PSA density ranges upto 0.25 ng/ml/cm3. The Area Under the Curve (AUC) for PSA and PSAD was 0.876 and 0.884 respectively. Only one patient (0.43%) had post-biopsy complication (acute bacterial prostatitis) requiring hospital admission. Conclusion The current serum PSA and PSAD cut

  4. High-yield biopsy technique for subepidermal blisters.

    PubMed

    Braswell, Mark A; McCowan, Nancye K; Schulmeier, Jennifer S; Brodell, Robert T

    2015-04-01

    Dermatologists often perform 2 biopsies in patients with widespread tense blisters: one for light microscopy and another for direct immunofluorescence (DIF). Biopsy techniques recommended for blistering diseases with tense blisters are discussed, and illustrations demonstrate an alternative approach utilizing a single punch biopsy. A single punch biopsy is more cost effective and provides the same diagnostic information as the standard 2-biopsy approach for subepidermal blisters plus additional salt-split skin-like diagnostic information. A limitation for bisecting the single punch biopsy specimen is a potential complete separation of the epidermis from the dermis. The single punch biopsy technique is a simple cost-effective method for obtaining necessary diagnostic information when sampling tense blisters in patients with blistering diseases.

  5. Understanding the diagnostic yield of current endoscopic biopsy for gastric neoplasm

    PubMed Central

    Kwack, Won G.; Ho, Won J.; Kim, Jae H.; Lee, Jin H.; Kim, Eo J.; Kang, Hyoun W.; Lee, Jun K.

    2016-01-01

    Abstract Although there are general guidelines on endoscopic biopsy for diagnosing gastric neoplasms, they are predominantly based on outdated literature obtained with fiberscopes without analyses specific to tumor characteristics. This study aims to comprehensively characterize the contemporary endoscopic biopsy by determining the diagnostic yield across different lesion morphologies and histological stages, especially exploring how the number and site of biopsy may influence the overall yield. Biopsy samples from suspected gastric neoplasms were collected prospectively from May 2011 to August 2014 in a tertiary care medical center. A standardized methodology was used to obtain a total of 6 specimens from 2 defined sites per lesion. Rate of positive diagnosis based on the biopsy number and site was assessed for specific gastric lesion morphologies and histological stages. A total of 1080 biopsies from 180 pathologically diagnosed neoplastic lesions in 176 patients were obtained during the study. For depressed/ulcerative and polypoid lesions, the yield was already >99% by the fourth biopsy without further gain from additional biopsies. Lower overall yield was observed for infiltrative lesions (57.1% from 4 biopsies). The site of biopsy did not influence the diagnostic yield except for with infiltrative lesions in which biopsies from thickened mucosal folds were of higher yield than erosive regions. Obtaining 4 specimens may be sufficient for accurate diagnosis of a depressed/ulcerative or polypoid gastric lesion regardless of its histological stage. For infiltrative lesions, at least 5 to 6 biopsies per lesion with more representative sampling from thickened mucosal folds may be preferable. PMID:27472689

  6. Biopsies

    MedlinePlus

    ... News Physician Resources Professions Site Index A-Z Biopsies - Overview A biopsy is the removal of tissue ... What are the limitations of biopsies? What are biopsies? A biopsy is the removal of tissue in ...

  7. Diagnostic yield of percutaneous biopsy for sclerotic bone lesions: Influence of mean Hounsfield units.

    PubMed

    Ní Mhuircheartaigh, Jennifer; McMahon, Colm; Lin, Yu-Ching; Wu, Jim

    2017-07-04

    To identify whether there was an association between Hounsfield units of sclerotic bone lesions and diagnostic yield of biopsy. All core needle biopsies of sclerotic bone lesion were identified from a database. Pathology reports were reviewed to determine whether the biopsy was diagnostic or non-diagnostic. 91 patients were included in the study group. The yield for lesions with mean HU≥500 was significantly lower than those with a mean HU≤500 (40% vs. 69.6%, p<0.05). Lesions with a mean HU>500 are more likely to have a non-diagnostic biopsy than a diagnostic biopsy. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. EUS-guided liver biopsy for parenchymal disease: a comparison of diagnostic yield between two core biopsy needles.

    PubMed

    Sey, Michael Sai Lai; Al-Haddad, Mohammad; Imperiale, Thomas F; McGreevy, Kathleen; Lin, Jingmei; DeWitt, John M

    2016-02-01

    EUS-guided biopsy of the liver has a variable diagnostic accuracy and specimen adequacy. A new core biopsy needle has been developed that may improve performance. The objective of this study was to compare the diagnostic yield of a new core biopsy needle with the previous standard needle. In this cross-sectional study, consecutive patients who underwent EUS-guided core liver biopsy over a 7-year period for suspected parenchymal disease were prospectively evaluated. Between 2007 and 2011, all biopsies were performed with a 19-gauge Tru-cut biopsy needle (Quick-core [QC]), whereas a novel reverse bevel needle (PC) was used exclusively from 2011 to 2014. All specimens were examined by 1 of 3 experienced, blinded pathologists for the following: presence of visible core, aggregate specimen length, number of complete portal tracts, and specimen adequacy. A total of 75 patients (mean age 51 years, 51 female) underwent liver biopsy by using the QC (n = 45) or PC (n = 30) needle. The QC and PC groups had similar demographics, indications for EUS, indications for liver biopsy, and liver findings on EUS. Compared with those of the QC, biopsies with the PC required fewer passes (median 2 vs 3; P < .0001) but produced longer aggregate length (median 20 mm vs 9 mm; P < .0001) with more complete portal tracts (median 5 vs 2; P = .0003) and adequate specimens (P < .01). Two patients had abdominal pain after liver biopsy with the QC needle. Compared with the QC needle, EUS-guided core liver biopsy with the PC needle produced longer aggregate length, more complete portal tracts, and more adequate specimens despite fewer passes (Clinical trial registration number: NCT00586313.). Copyright © 2016 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  9. Yield and complications of kidney biopsy over two decades in a tertiary pediatric center.

    PubMed

    Hod Feins, Roei; Tobar, Anna; Davidovits, Miriam

    2017-04-01

    Kidney biopsy serves as an adjunct for the diagnosis of renal disease, but it is not always productive. This study evaluated the yield and risks of kidney biopsies performed in 1995-2014 at a tertiary pediatric medical center. The medical files of all patients who underwent closed percutaneous biopsy for various indications in native or transplanted kidneys were retrospectively reviewed for patient characteristics, technical and histopathologic findings, biopsy yield, and biopsy complications. Biopsy yield was considered positive if findings confirmed a probable diagnosis or led to a change in clinical diagnosis, disease severity/activity grade, treatment strategy, or prognosis; and negative, if findings were non-informative and in cases of technical failure. During the study period, 216 biopsies were performed on native kidneys and 84 on transplanted kidneys. In the transplanted kidney group, the most common indications for biopsy were decreased glomerular filtration rate and suspected rejection. Rates of positive biopsy yield were 86.6% in the native kidney group and 82.1% in the transplanted kidney group; the difference was not statistically significant. Significant between-group differences were found in various technical and histopathological parameters, patient age at biopsy, and sex distribution. In the native kidney group, positive biopsy yield was associated with the presence of nephrotic-range proteinuria. Post-procedural complications occurred in three patients (1.3%) with native kidneys, and in one patient (1.1%) with a transplanted kidney. Kidney biopsy is an efficient and safe procedure in both native and transplanted kidneys and provides helpful diagnostic information in most cases in which it is deemed necessary. © 2016 Japan Pediatric Society.

  10. [Diagnostic yield and postoperative management of patients submitted to brain biopsy in a university hospital].

    PubMed

    Gracia, Isabel; Perelló, Laura; Valero, Ricard; Hervías, Adriana; Perdomo, Juan; Pujol, Roger; González, Josep; Hurtado, Paola; de Riva, Nicolás; Tercero, Francisco Javier; Carrero, Enrique; Ferrer, Enric; Fàbregas, Neus

    2015-01-01

    To assess the diagnostic yield and the incidence of perioperative complications in patients undergoing an open or closed cerebral biopsy and to determine the length of intensive care monitoring, for early diagnosis and fast management of perioperative complications. This was a retrospective analysis of all the patients that underwent brain biopsy between January 2006 and July 2012. We recorded demographic data, comorbidities, modality of biopsy, intraoperative clinical data, histological results, computed tomography scanning findings and occurrence, and type of perioperative complications and moment of appearance. Seventy-six brain biopsies in 75 consecutive patients (51 closed and 25 open) were analysed. Diagnostic yield was 98% for closed biopsies and 96% for open biopsies. Mortality related to the procedures was 3.9 and 4%, respectively. The incidence of major complications was 3.9% for closed biopsies and 8% for open biopsies; half of these appeared within the first 24 postoperative hours, during patient stay in the Intensive Care Unit. Age was the only risk factor for complications (P=.04) in our study. No differences in morbimortality were found between the studied groups. Diagnostic yield was very high in our series. Because the importance of early diagnosis of complications for preventing long-term sequelae, we recommend overnight hospital stay for observation after open or closed brain biopsy. Copyright © 2014 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  11. Real-time magnetic resonance imaging guidance improves the diagnostic yield of endomyocardial biopsy

    PubMed Central

    Rogers, Toby; Ratnayaka, Kanishka; Karmarkar, Parag; Campbell-Washburn, Adrienne E.; Schenke, William H.; Mazal, Jonathan R.; Kocaturk, Ozgur; Faranesh, Anthony Z.; Lederman, Robert J.

    2016-01-01

    Background Diagnostic yield of endomyocardial biopsy is low, particularly in disease that affects the myocardium in a non-uniform distribution. We hypothesized that real-time MRI guidance could improve the yield through targeted biopsy of focal myocardial pathology. Methods An animal model of focal myocardial pathology was created by infusing 3mL of fluorescent microspheres (NuFlow Hydrocoat, 15μm diameter, 5 million spheres/mL) followed by 2mL of 100% ethanol to a branch coronary artery. Animals were survived for minimum 14days, before undergoing MRI guided endomyocardial biopsy using a custom 6.5Fr active visualization MRI-conditional bioptome and X-ray guided biopsy using a commercial bioptome. Specimens were analyzed using a dissecting microscope under ultraviolet light to determine the proportion of ‘on-target’ specimens containing fluorescent microspheres. Results A total of 77 specimens were obtained using real-time MRI guidance and 87 using X-ray guidance, in five animals. Specimens obtained with the MRI-conditional bioptome were smaller compared with the commercial X-ray bioptome. Real-time MRI guidance significantly increased the diagnostic yield of endomyocardial biopsy (82% vs. 56% on-target biopsy specimens with real-time MRI vs. X-ray guidance, p<0.01). Conclusions Endomyocardial biopsy performed using real-time MRI guidance is feasible and significantly improves the diagnostic yield compared with X-ray fluoroscopy guidance. PMID:27631028

  12. Frameless robotically targeted stereotactic brain biopsy: feasibility, diagnostic yield, and safety.

    PubMed

    Bekelis, Kimon; Radwan, Tarek A; Desai, Atman; Roberts, David W

    2012-05-01

    Frameless stereotactic brain biopsy has become an established procedure in many neurosurgical centers worldwide. Robotic modifications of image-guided frameless stereotaxy hold promise for making these procedures safer, more effective, and more efficient. The authors hypothesized that robotic brain biopsy is a safe, accurate procedure, with a high diagnostic yield and a safety profile comparable to other stereotactic biopsy methods. This retrospective study included 41 patients undergoing frameless stereotactic brain biopsy of lesions (mean size 2.9 cm) for diagnostic purposes. All patients underwent image-guided, robotic biopsy in which the SurgiScope system was used in conjunction with scalp fiducial markers and a preoperatively selected target and trajectory. Forty-five procedures, with 50 supratentorial targets selected, were performed. The mean operative time was 44.6 minutes for the robotic biopsy procedures. This decreased over the second half of the study by 37%, from 54.7 to 34.5 minutes (p < 0.025). The diagnostic yield was 97.8% per procedure, with a second procedure being diagnostic in the single nondiagnostic case. Complications included one transient worsening of a preexisting deficit (2%) and another deficit that was permanent (2%). There were no infections. Robotic biopsy involving a preselected target and trajectory is safe, accurate, efficient, and comparable to other procedures employing either frame-based stereotaxy or frameless, nonrobotic stereotaxy. It permits biopsy in all patients, including those with small target lesions. Robotic biopsy planning facilitates careful preoperative study and optimization of needle trajectory to avoid sulcal vessels, bridging veins, and ventricular penetration.

  13. Understanding the diagnostic yield of current endoscopic biopsy for gastric neoplasm: A prospective single-center analysis based on tumor characteristics stratified by biopsy number and site.

    PubMed

    Kwack, Won G; Ho, Won J; Kim, Jae H; Lee, Jin H; Kim, Eo J; Kang, Hyoun W; Lee, Jun K

    2016-07-01

    Although there are general guidelines on endoscopic biopsy for diagnosing gastric neoplasms, they are predominantly based on outdated literature obtained with fiberscopes without analyses specific to tumor characteristics.This study aims to comprehensively characterize the contemporary endoscopic biopsy by determining the diagnostic yield across different lesion morphologies and histological stages, especially exploring how the number and site of biopsy may influence the overall yield.Biopsy samples from suspected gastric neoplasms were collected prospectively from May 2011 to August 2014 in a tertiary care medical center. A standardized methodology was used to obtain a total of 6 specimens from 2 defined sites per lesion. Rate of positive diagnosis based on the biopsy number and site was assessed for specific gastric lesion morphologies and histological stages.A total of 1080 biopsies from 180 pathologically diagnosed neoplastic lesions in 176 patients were obtained during the study. For depressed/ulcerative and polypoid lesions, the yield was already >99% by the fourth biopsy without further gain from additional biopsies. Lower overall yield was observed for infiltrative lesions (57.1% from 4 biopsies). The site of biopsy did not influence the diagnostic yield except for with infiltrative lesions in which biopsies from thickened mucosal folds were of higher yield than erosive regions.Obtaining 4 specimens may be sufficient for accurate diagnosis of a depressed/ulcerative or polypoid gastric lesion regardless of its histological stage. For infiltrative lesions, at least 5 to 6 biopsies per lesion with more representative sampling from thickened mucosal folds may be preferable.

  14. Low yield of routine duodenal biopsies for evaluation of abdominal pain

    PubMed Central

    Dubin, Sterling M; Kwong, Wilson T; Kalmaz, Denise; Savides, Thomas J

    2015-01-01

    AIM: To determine the yield of biopsying normal duodenal mucosa for investigation of abdominal pain. METHODS: This is a retrospective chart review of consecutive patients who underwent esophagogastroduodenoscopy (EGD) with duodenal biopsies of normal appearing duodenal mucosa for an indication that included abdominal pain. All the patients in this study were identified from an electronic endoscopy database at a single academic medical center and had an EGD with duodenal biopsies performed over a 4-year period. New diagnoses that were made as a direct result of duodenal biopsies were identified. All duodenal pathology reports and endoscopy records were reviewed for indications to perform the examination as well as the findings; all the medical records were reviewed. Exclusion criteria included age less than 18 years, duodenal mass, nodule, or polyp, endoscopic duodenitis, duodenal scalloping, known celiac disease, positive celiac serology, Crohns disease, or history of bone marrow transplant. Information was collected in a de-identified database with pertinent demographic information including human immunodeficiency virus (HIV) status, and descriptive statistics were performed. RESULTS: About 300 patients underwent EGD with biopsies of benign appearing or normal appearing duodenal mucosa. The mean age of patients was 44.1 ± 16.8 years; 189 of 300 (63%) were female. A mean of 4.3 duodenal biopsies were performed in each patient. In the subgroup of patients with abdominal pain without anemia, diarrhea, or weight loss the mean age was 43.4 ± 16.3 years. Duodenal biopsies performed for an indication that included abdominal pain resulting in 4 new diagnoses (3 celiac disease and 1 giardiasis) for an overall yield of 1.3%. 183 patients with abdominal pain without anemia, diarrhea, or weight loss (out of the total 300 patients) underwent duodenal biopsy of duodenal mucosa resulting in three new diagnoses (two cases of celiac disease and one giardiasis) for a yield of 1

  15. Low yield of routine duodenal biopsies for evaluation of abdominal pain.

    PubMed

    Dubin, Sterling M; Kwong, Wilson T; Kalmaz, Denise; Savides, Thomas J

    2015-06-28

    To determine the yield of biopsying normal duodenal mucosa for investigation of abdominal pain. This is a retrospective chart review of consecutive patients who underwent esophagogastroduodenoscopy (EGD) with duodenal biopsies of normal appearing duodenal mucosa for an indication that included abdominal pain. All the patients in this study were identified from an electronic endoscopy database at a single academic medical center and had an EGD with duodenal biopsies performed over a 4-year period. New diagnoses that were made as a direct result of duodenal biopsies were identified. All duodenal pathology reports and endoscopy records were reviewed for indications to perform the examination as well as the findings; all the medical records were reviewed. Exclusion criteria included age less than 18 years, duodenal mass, nodule, or polyp, endoscopic duodenitis, duodenal scalloping, known celiac disease, positive celiac serology, Crohns disease, or history of bone marrow transplant. Information was collected in a de-identified database with pertinent demographic information including human immunodeficiency virus (HIV) status, and descriptive statistics were performed. About 300 patients underwent EGD with biopsies of benign appearing or normal appearing duodenal mucosa. The mean age of patients was 44.1 ± 16.8 years; 189 of 300 (63%) were female. A mean of 4.3 duodenal biopsies were performed in each patient. In the subgroup of patients with abdominal pain without anemia, diarrhea, or weight loss the mean age was 43.4 ± 16.3 years. Duodenal biopsies performed for an indication that included abdominal pain resulting in 4 new diagnoses (3 celiac disease and 1 giardiasis) for an overall yield of 1.3%. 183 patients with abdominal pain without anemia, diarrhea, or weight loss (out of the total 300 patients) underwent duodenal biopsy of duodenal mucosa resulting in three new diagnoses (two cases of celiac disease and one giardiasis) for a yield of 1.6%. Duodenal biopsies of

  16. Histopathological yield in different types of bronchoscopic biopsies in proven cases of pulmonary tuberculosis.

    PubMed

    Gupta, Nalini; Singh, Gurmeet C; Rana, Manoj K

    2015-01-01

    Diagnosis of pulmonary tuberculosis (TB) is difficult and often requires a lung biopsy. The goal of this retrospective study was to determine the histopathological parameters useful for diagnosis of pulmonary TB in different types of bronchoscopic biopsies (transbronchial lung biopsy [TBLB], transbronchial needle aspiration [TBNA], and bronchial biopsy [BB]). The records of patients diagnosed to have pulmonary TB, over a period of 1-year were evaluated. Patients with positive acid-fast bacilli (AFB) culture and with three bronchoscopic biopsies including TBLB, TBNA, and BB were included in the study. Selected (14) histological parameters were evaluated retrospectively in a total of 27 biopsies from 9 patients with TB after hematoxylin-eosin and Ziehl-Neelsen staining. Diagnostic yield in TBLBs and TBNA was similar for granulomas detection (66.6% each). Granulomas in TBNA were larger, caseating and confluent as compared to small interstitial granulomas seen in TBLB. AFB was demonstrated in only one patient in TBNA. Lymphocytic cell cuffing was seen around most TBLB granulomas. One patient also showed microfilaria in blood vessel in TBLB. BBs in all patients showed the presence of goblet cell metaplasia and increased peribronchial plasma cell infiltrate with or without eosinophils may be indicative of chronic injury. The yield of granulomas was low in BBs seen in only 2 patients (22.2%). Diagnostic yield of TBNA and TBLB for granulomas was similar; however, caseation was seen more frequently in TBNA than on TBLB. Of other histological parameters, bronchial metaplastic changes and peribronchial plasma cells infiltrate were constant findings in all tubercular biopsies indicative of chronic injury.

  17. The yield of colonic biopsy in the evaluation of chronic unexplained diarrhea.

    PubMed

    Genta, Robert M; Sonnenberg, Amnon

    2015-08-01

    In clinical practice, colonoscopy is widely used for the workup of chronic unexplained diarrhea. The aim of this study was to determine the yield of colonic biopsy in such an endeavor. In a computerized database of 130 204 patients evaluated for chronic diarrhea, we tested the influence of biopsy site, number of tissue fragments, patient symptoms, and indication on the outcome of histopathologic evaluation. The population comprised 69% women and 31% men aged (mean±SD) 52.8±17.4 years. In 19% of patients, histopathological analysis revealed various types of mucosal lesion, the most common being microscopic colitis (8.6%), ulcerative colitis (2.2%), Crohn's disease (0.6%), active colitis (5.0%), diverticulitis (0.1%), and colonic ischemia (0.5%). In 29% of patients, the colonoscopy also revealed the presence of colon polyps. Endoscopists tended to take significantly more tissue samples from endoscopically visible lesions than for random biopsies of macroscopically normal-appearing mucosa. Overall, these associations suggest that specific diagnoses lead to more biopsies, rather than more biopsies leading to more diagnoses. Colonoscopy is a successful tool in the workup of chronic diarrhea, yielding a definitive diagnosis in almost one-fifth of all patients. As an added benefit, it also contributes to cancer prevention through the incidental findings of colonic neoplasm.

  18. Improving diagnostic yield in brain biopsy: coupling spectroscopic targeting with real-time needle placement.

    PubMed

    Hall, W A; Martin, A; Liu, H; Truwit, C L

    2001-01-01

    The purpose of this study was to determine the utility of intraoperative magnetic resonance spectroscopy (MRS) for targeting during brain biopsy using a skull-mounted trajectory guide. From January 1999 to January 2001, 17 patients had intraoperative MRS-guided brain biopsy using a trajectory guide. Ten had turbo spectroscopic imaging (TSI), and seven had both SVS (single-voxel spectroscopy) and TSI. Prospective stereotaxy was used to align the device in a short-bore 1.5-T MR scanner. Areas of elevated choline relative to creatine on SVS and TSI were targeted during the biopsy. Intraoperative imaging confirmed appropriate positioning of the biopsy needle at the time of tissue sampling in all cases. All 17 biopsies (100%) yielded diagnostic tissue. Six patients (34%) had glioblastomas multiforme, three (18%) had anaplastic astrocytomas, three (18%) had anaplastic oligodendrogliomas, two (12%) had radiation necrosis, and one each (6%) had germinoma, ganglioglioma, and astrocytoma. Postoperative imaging confirmed the absence of clinically and radiographically relevant hemorrhage. The findings on SVS correlated with the pathology in all seven cases (100%). In 13 of 17 patients (76%) who had TSI, the spectra correlated well with the permanent pathologic examination. The SVS and TSI spectra were similar in six of seven (86%) cases. Intraoperative MRS-guided brain biopsy using a trajectory guide is a simple, safe, and accurate technique for accessing areas of the brain of diagnostic interest. J. Magn. Reson. Imaging 2001;13:12-15. Copyright 2001 Wiley-Liss, Inc.

  19. Biopsy

    MedlinePlus

    ... Nemcek AA. Percutaneous biopsy. In: Mauro MA, Murphy KPJ, Thomson KR, Venbrux AC, Morgan RA, eds. Image- ... by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is ...

  20. Biopsy case mix and diagnostic yield at a Malawian central hospital.

    PubMed

    Mtonga, P; Masamba, L; Milner, D; Shulman, L N; Nyirenda, R; Mwafulirwa, K

    2013-09-01

    Cancer is a major disease burden worldwide resulting in high morbidity and mortality. It is the leading cause of mortality in developed countries and is one of the three leading causes of death for adults in developing countries. Pathological examination of tissue biopsies with histological confirmation of a correct cancer diagnosis is central to cancer care. Without an accurate and specific pathologic diagnosis, effective treatment cannot be planned or delivered. In addition, there are marked geographical variations in incidence of cancer overall, and of the specific cancers seen. Much of the published literature on cancer incidence in developing countries reflects gross estimates and may not reflect reality. Performing baseline studies to understand these distributions lays the groundwork for further research in this area of cancer epidemiology. Our current study surveys and ranks cancer diagnoses by individual anatomical site at Queen Elizabeth Central Hospital (QECH) which is the largest teaching and referral hospital in Malawi. A retrospective study was conducted reviewing available pathology reports over a period of one full year from January 2010 to December 2010 for biopsies from patients suspected clinically of having cancer. There were 544 biopsies of suspected cancer, taken from 96 anatomical sites. The oesophagus was the most common biopsied site followed by breast, bladder, bone, prostate, bowel, and cervical lymph node. Malignancies were found in biopsies of the oesophagus biopsies (squamous cell carcinoma, 65.1%; adenocarcinoma, 11.6%), breast (57.5%), bladder (squamous cell carcinoma, 53.1%) and stomach (37.6%). Our study demonstrates that the yield of biopsy for clinically suspected malignancy was greater than 50% for the 11 most common sites and provides a current survey of cancer types by site present in the population reporting to our hospital.

  1. Post clamp

    NASA Technical Reports Server (NTRS)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  2. Diagnostic Yield for Cancer and Diagnostic Accuracy of Computed Tomography-guided Core Needle Biopsy of Subsolid Pulmonary Lesions.

    PubMed

    Munir, Sohaib; Koppikar, Sahil; Hopman, Wilma M; Boag, Alexander H; Dhillon, Gurmohan; Salahudeen, Shafeequr Rahman; Nolan, Robert L; Flood, Justin

    2017-01-01

    We aimed to determine the diagnostic yield for cancer and diagnostic accuracy of computed tomography-guided core needle biopsy (CTNB) in subsolid pulmonary lesions. Fifty-two biopsies of 52 subsolid lesions in 51 patients were identified from a database of 912 lung biopsies and analyzed for the diagnostic yield for cancer and diagnostic accuracy of core CTNB diagnosis as well as complication rates. When indeterminate biopsy results were included in the analysis, the diagnostic yield for cancer was 80.8% and the diagnostic accuracy of core needle biopsy was 84.6% (n=52). It was 85.7% and 91.7%, respectively, when indeterminate results were excluded (n=48) and 82.4% and 82.4%, respectively, for biopsies with surgical confirmation (n=17). Attenuation was statistically significant for diagnostic yield for cancer (P=0.028) and diagnostic accuracy of core needle biopsy (P=0.001) when the indeterminate results were excluded (n=48). Attenuation and size were not statistically significant for diagnostic yield for cancer and diagnostic accuracy of needle biopsy (n=52), and size was not statistically significant for either when the indeterminate results were excluded. These results were achieved without any major complications as per the Society of Interventional Radiology Standards of Practice. CTNB offers a high yield in establishing a histopathologic diagnosis of subsolid pulmonary lesions, with both ground-glass and solid-predominance. The pure ground-glass category of lesions requires further research to determine the true diagnostic yield and diagnostic accuracy of core needle biopsies.

  3. Diagnostic yield of nondiagnostic thyroid nodules is not altered by timing of repeat biopsy.

    PubMed

    Lubitz, Carrie C; Nagarkatti, Sushruta S; Faquin, William C; Samir, Anthony E; Hassan, Maria C; Barbesino, Giuseppe; Ross, Douglas S; Randolph, Gregory W; Gaz, Randall D; Stephen, Antonia E; Hodin, Richard A; Daniels, Gilbert H; Parangi, Sareh

    2012-06-01

    Guidelines from the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference recommend a repeat fine-needle aspiration biopsy (FNAB) after 3 months for thyroid nodules with a nondiagnostic (ND) result. Our aims were to assess which factors influenced their clinical management and to determine if the timing of the repeat FNAB affects the diagnostic yield. A retrospective institutional review of 298 patients from 1/2006 to 12/2007 with an ND FNAB was performed. The factors influencing the next step in management, including age, gender, history of radiation, presence of Hashimoto's thyroiditis, thyroid-stimulating hormone levels, and ultrasound characteristics, were evaluated. The effect of the time of the repeat FNABs on their diagnostic yield was assessed. Of the 298 patients in our cohort, 9% were referred directly for surgery, 76% had a repeat FNAB, and 15% were observed. Tumor size was the only independent variable correlated with treatment strategy after a ND FNAB. There was not a significant difference in diagnostic yields between repeat FNABs performed earlier than 3 months compared to those preformed later (p=0.58). The timing of repeat FNAB for an initial ND FNAB does not affect diagnostic yield of the repeat FNAB.

  4. Diagnostic Yield of Nondiagnostic Thyroid Nodules Is Not Altered by Timing of Repeat Biopsy

    PubMed Central

    Nagarkatti, Sushruta S.; Faquin, William C.; Samir, Anthony E.; Hassan, Maria C.; Barbesino, Giuseppe; Ross, Douglas S.; Randolph, Gregory W.; Gaz, Randall D.; Stephen, Antonia E.; Hodin, Richard A.; Daniels, Gilbert H.; Parangi, Sareh

    2012-01-01

    Background Guidelines from the National Cancer Institute Thyroid Fine Needle Aspiration State of the Science Conference recommend a repeat fine-needle aspiration biopsy (FNAB) after 3 months for thyroid nodules with a nondiagnostic (ND) result. Our aims were to assess which factors influenced their clinical management and to determine if the timing of the repeat FNAB affects the diagnostic yield. Methods A retrospective institutional review of 298 patients from 1/2006 to 12/2007 with an ND FNAB was performed. The factors influencing the next step in management, including age, gender, history of radiation, presence of Hashimoto's thyroiditis, thyroid-stimulating hormone levels, and ultrasound characteristics, were evaluated. The effect of the time of the repeat FNABs on their diagnostic yield was assessed. Results Of the 298 patients in our cohort, 9% were referred directly for surgery, 76% had a repeat FNAB, and 15% were observed. Tumor size was the only independent variable correlated with treatment strategy after a ND FNAB. There was not a significant difference in diagnostic yields between repeat FNABs performed earlier than 3 months compared to those preformed later (p=0.58). Conclusion The timing of repeat FNAB for an initial ND FNAB does not affect diagnostic yield of the repeat FNAB. PMID:22667452

  5. Combined bronchoalveolar lavage and transbronchial lung biopsy: safety and yield in ventilated patients.

    PubMed

    Bulpa, P A; Dive, A M; Mertens, L; Delos, M A; Jamart, J; Evrard, P A; Gonzalez, M R; Installé, E J

    2003-03-01

    The aim of this study was to evaluate the safety and diagnostic yield of bedside bronchoalveolar lavage (BAL) combined with fibrescopic transbronchial lung biopsy (TBLB) in determining the aetiology of pulmonary infiltrates in mechanically ventilated patients. The records of 38 mechanically ventilated patients who underwent BAL/TBLB to investigate unexplained pulmonary infiltrates were retrospectively reviewed. Patients were divided into two groups: immunocompetent (group 1: n = 22; group 1a: n = 11, late acute respiratory distress syndrome (ARDS); group 1b: n = 11, no ARDS) and immunocompromised (group 2, n=16). The procedure allowed a diagnosis in 28 patients (74%), inducing therapeutic modification in 24 (63%) and confirmation of clinical diagnosis in four (11%). In groups 1a, 1b and 2, diagnosis was obtained in 11 out of 11 (fibroproliferation), seven out of 11 and 10 out of 16 patients, and therapy changed in 11 out of 11 (administration of steroids), six out of 11 and seven out of 16 patients, respectively. Pneumothorax occurred in nine patients (four of group 1a), bleeding in four (<35 mL), and transient hypotension in two. No fatalities were procedure-related. Combined bronchoalveolar lavage/transbronchial lung biopsy is of diagnostic and therapeutic value in mechanically ventilated patients with unexplained pulmonary infiltrates, excluding those with late acute respiratory distress syndrome. Although complications are to be expected, the benefits of the procedure appear to exceed the risks in patients in whom a histological diagnosis is deemed necessary.

  6. Imaging, procedural and clinical variables associated with tumor yield on bone biopsy in metastatic castration-resistant prostate cancer.

    PubMed

    McKay, R R; Zukotynski, K A; Werner, L; Voznesensky, O; Wu, J S; Smith, S E; Jiang, Z; Melnick, K; Yuan, X; Kantoff, P W; Montgomery, B; Balk, S P; Taplin, M-E

    2014-12-01

    Understanding the mechanisms driving disease progression is fundamental to identifying new therapeutic targets for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC). Owing to the prevalence of bone metastases in mCRPC, obtaining sufficient tumor tissue for analysis has historically been a challenge. In this exploratory analysis, we evaluated imaging, procedural and clinical variables associated with tumor yield on image-guided bone biopsy in men with mCRPC. Clinical data were collected prospectively from men with mCRPC enrolled on a phase II trial with serial metastasis biopsies performed according to standard clinical protocol. Imaging was retrospectively reviewed. We evaluated the percent positive biopsy cores (PPC), calculated as the number of positive cores divided by the total number of cores collected per biopsy. Twenty-nine men had 39 bone biopsies. Seventy-seven percent of bone biopsies had at least one positive biopsy core. We determined that lesion size and distance from the skin to the lesion edge correlated with tumor yield on biopsy (median PPC 75% versus 42% for lesions >8.8 cm(3) versus ⩽ 8.8 cm(3), respectively, P=0.05; median PPC 33% versus 71% for distance ⩾ 6.1 versus <6.1 cm, respectively, P = 0.02). There was a trend towards increased tumor yield in patients with increased uptake on radionuclide bone scan, higher calcium levels and shorter duration of osteoclast-targeting therapy, although this was not statistically significant. Ten men had 14 soft tissue biopsies. All soft tissue biopsies had at least one positive biopsy core. This exploratory analysis suggests that there are imaging, procedural and clinical variables that have an impact on image-guided bone biopsy yield. In order to maximize harvest of prostate cancer tissue, we have incorporated a prospective analysis of the metrics described here as part of a multi-institutional project aiming to use the molecular characterization of mCRPC tumors to

  7. Multimodal optical biopsy probe to improve the safety and diagnostic yield of brain needle biopsies (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Desroches, Joannie; Pichette, Julien; Goyette, Andréanne; Tremblay, Marie-Andrée.; Jermyn, Michael; Petrecca, Kevin; Leblond, Frédéric

    2016-03-01

    Brain needle biopsy (BNB) is performed to collect tissue when precise neuropathological diagnosis is required to provide information about tumor type, grade, and growth patterns. The principal risks associated with this procedure are intracranial hemorrhage (due to clipping blood vessels during tissue extraction), incorrect tumor typing/grading due to non-representative or non-diagnostic samples (e.g. necrotic tissue), and missing the lesion. We present an innovative device using sub-diffuse optical tomography to detect blood vessels and Raman spectroscopy to detect molecular differences between tissue types, in order to reduce the risks of misdiagnosis, incorrect tumour grading, and non-diagnostic samples. The needle probe integrates optical fibers directly onto the external cannula of a commercial BNB needle, and can perform measurements for both optical techniques through the same fibers. This integrated optical spectroscopy system uses diffuse reflectance signals to perform a 360-degree reconstruction of the tissue adjacent to the biopsy needle, based on the optical contrast associated with hemoglobin light absorption, thereby localizing blood vessels. Raman spectra measurements are also performed interstitially for tissue characterization. A detailed sensitivity of the system is presented to demonstrate that it can detect absorbers with diameters <300 µm located up to ˜2 mm from the biopsy needle core, for bulk optical properties consistent with brain tissue. Results from animal experiments are presented to validate blood vessel detection and Raman spectrum measurement without disruption of the surgical workflow. We also present phantom measurements of Raman spectra with the needle probe and a comparison with a clinically validated Raman spectroscopy probe.

  8. Using polarization-sensitive optical coherence tomography to identify tumor stromal fibrosis and increase tumor biopsy yield (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Hariri, Lida P.; Adams, David C.; Miller, Alyssa J.; Mino-Kenudson, Mari; Suter, Melissa J.

    2016-03-01

    Tissue biopsy is the principal method used to diagnose tumors in a variety of organ systems. It is essential to maximize tumor yield in biopsy specimens for both clinical diagnostic and research purposes. This is particularly important in tumors where additional tissue is needed for molecular analysis to identify patients who would benefit from mutation-specific targeted therapy, such as in lung carcinomas. Inadvertent sampling of fibrotic stroma within tumor nodules contaminates biopsies, decreases tumor yield, and can impede diagnosis. The ability to assess tumor composition and guide biopsy site selection in real time is likely to improve diagnostic yield. Polarization sensitive OCT (PS-OCT) measures birefringence in organized tissues, such as collagen, and could be used to distinguish tumor from fibrosis. In this study, PS-OCT was obtained in 65 lung nodule samples from surgical resection specimens containing varying ratios of tumor and fibrosis. PS-OCT was obtained with either a custom-built helical scanning catheter (0.8 or 1.6mm in diameter) or a dual-axis bench top scanner. Strong birefringence was observed in nodules containing dense fibrosis, with no birefringence in adjacent regions of tumor. Tumors admixed with early, loosely-organized collagen demonstrated mild-to-moderate birefringence, and tumors with little collagen content showed little to no birefringent signal. PS-OCT provides significant insights into tumor nodule composition, and has potential to differentiate tumor from stromal fibrosis during biopsy site selection to increase diagnostic tumor yield.

  9. Modified Core Biopsy Technique to Increase Diagnostic Yields for Well-Circumscribed Indeterminate Thyroid Nodules: A Retrospective Analysis.

    PubMed

    Han, S; Shin, J H; Hahn, S Y; Oh, Y L

    2016-06-01

    The results of conventional core biopsy for some thyroid nodules with indeterminate cytology have still remained indeterminate. The aim of this study was to evaluate whether the ultrasonography-guided core needle biopsy technique containing the nodule, capsular portion, and surrounding parenchyma was more effective than a conventional method in enhancing diagnostic yield for circumscribed solid thyroid nodules without malignant sonographic features. This retrospective comparative study evaluated 26 thyroid nodules in 26 consecutive patients between 2006 and 2010. They were biopsied by using a conventional method, and 61 nodules from 60 patients were biopsied by using a modified ultrasonography-guided core needle biopsy technique in 2013. The patients enrolled in this study presented with circumscribed solid thyroid nodules without malignant sonographic features, classified as nondiagnostic or atypia/follicular lesions of undetermined significance at previous cytology. The ultrasonography-guided core needle biopsy results of the 2 groups were compared. The rate of inconclusive ultrasonography-guided core needle biopsy results was 34.6% (9/26) in the conventional group and 11.4% (7/61) in the modified technique group (P = .018). There was no significant difference in the mean size of the nodules between the 2 groups (P = .134). The malignancy rate was 33% (3/9) for the conventional group and 52% (27/52) for the modified technique group (P = .473). The most common malignant pathology was a follicular variant of papillary thyroid carcinoma and follicular adenoma was the most common benign lesion. For circumscribed solid nodules without malignant sonographic features with indeterminate cytology, the ultrasonography-guided core needle biopsy technique containing the nodule, capsular portion, and surrounding parenchyma is more effective in diagnostic yield compared with a conventional method that biopsies the intranodular portion. © 2016 by American Journal of

  10. Rigid clamp

    DOEpatents

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  11. Rigid clamp

    DOEpatents

    Benavides, G.L.; Burt, J.D.

    1994-07-12

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object. 12 figs.

  12. First-Line Use of Core Needle Biopsy for High-Yield Preliminary Diagnosis of Thyroid Nodules.

    PubMed

    Kim, H C; Kim, Y J; Han, H Y; Yi, J M; Baek, J H; Park, S Y; Seo, J Y; Kim, K W

    2017-02-01

    Although core needle biopsy was introduced as a diagnostic alternative to fine-needle aspiration, the utility and safety of core needle biopsy for thyroid nodules in a large population has yet to be studied comprehensively. We evaluate core needle biopsy yields on a large-scale basis to investigate its potential in the preliminary diagnosis of thyroid nodules. Between March 2005 and December 2013, 2448 initially detected thyroid nodules from 2120 consecutive patients who underwent core needle biopsy were retrospectively evaluated. Of these, 72 thyroid nodules from 63 patients were excluded due to prior fine-needle aspiration attempts. The inconclusive and conclusive result rates, diagnostic accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and unnecessary surgery rate of core needle biopsy were evaluated. With core needle biopsy as the first-line method, the inconclusive result rate was 11.9% (283/2376) and the conclusive result rate was 88.1% (2093/2376). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of core needle biopsy for the diagnosis of malignancy were 96.7% (1160/1200), 89.7% (347/387), 100% (813/813), 100% (347/347), and 95.3% (813/853), respectively. There were no major complications and 12 minor complications. We have demonstrated that first-line use of core needle biopsy may well improve diagnostic accuracy in thyroid nodules, reducing inconclusive or false-negative results and unnecessary operations. Such benefits underscore the promising role of core needle biopsy in managing thyroid nodules and optimizing related surgical decision-making. © 2017 by American Journal of Neuroradiology.

  13. The diagnostic yield and complications of open lung biopsies in kidney transplant patients with pulmonary disease

    PubMed Central

    Tomotani, Daniere Yurie Vieira; Pacheco, Eduardo Souza; de Sandes-Freitas, Tainá Veras; Viana, Laila Almeida; de Oliveira Pontes, Edgar Porto; Tamura, Nikkei; Tedesco-Silva, Hélio; Machado, Flavia Ribeiro; Freitas, Flávio Geraldo Rezende

    2017-01-01

    Background The purpose of this study was to assess the efficacy of open lung biopsy (OLB) in determining the specific diagnosis and the related complications in patients with undiagnosed diffuse pulmonary infiltrates. Methods This single center, retrospective study included adult kidney transplant patients who underwent OLB. The patients had diffuse pulmonary infiltrates without definitive diagnoses and failed to respond to empiric antibiotic treatment. We analyzed the number of specific diagnoses, changes in treatment and the occurrence of complications in these patients. A logistic regression was used to determine which variables were predictors of hospital mortality. Results From April 2010 to April 2014, 87 patients consecutively underwent OLB. A specific diagnosis was reached in 74 (85.1%) patients. In 46 patients (53%), their therapeutic management was changed after the OLB results. Twenty-five (28.7%) patients had complications related to the OLB. The hospital mortality rate was 25.2%. Age, SAPS3 score and complications related to the procedure were independent predictors of all-cause mortality. Conclusions OLB is a high-risk procedure with a high diagnostic yield in kidney transplant patients with diffuse pulmonary infiltrates who did not have a definitive diagnosis and who failed to respond to empiric antibiotic treatment. Complications related to OLB were common and were independently associated with intra-hospital mortality. PMID:28203420

  14. Diagnostic yield of a biopsy performed immediately after lung radiofrequency ablation.

    PubMed

    Tselikas, Lambros; de Baere, Thierry; Deschamps, Frederic; Hakimé, Antoine; Besse, Benjamin; Teriitehau, Christophe; de Montpreville, Vincent; Adam, Julien

    2017-03-01

    To evaluate the diagnostic performance of lung biopsies performed immediately after radiofrequency ablation (RFA). Twenty consecutive patients were treated with lung RFA. A biopsy was performed immediately after RFA, through the cannula used to insert the RFA probe to avoid hampering the RFA probe placement. Biopsies were analysed for diagnostic of malignancy and tumour morphological characteristics. Recurrence of RFA and procedure-related complications are reported. Mean tumour size was 17.3 mm (±6.2 mm). Ninety per cent (18/20) of biopsies were able to help diagnose malignancy. Cancer subtype and origin were determined in 70 % (14/20) of tumours, including 12 metastases and two primary lung cancers. During a median follow-up of 24 months, one tumour demonstrated local progression (5 %). The overall survival, lung disease-free survival and progression-free survival rates at 12 months were 100 %, 75 % and 65 %, respectively. Adverse events of the procedure including RFA and biopsy were five pneumothoraces requiring chest tube placement (25 %), seven minor pneumothoraces (35 %) and one subsegmental intrapulmonary haemorrhage (5 %) not requiring any treatment. A biopsy performed immediately after lung RFA allowed diagnosis of malignancy in 90 % of cases. This diagnosis is obtained without the need for additional puncture and does not hamper the accuracy of the initial RF probe placement. • Treatment and biopsy are feasible during the same procedure, avoiding multiple punctures. • The best puncture path can be preserved to treat the lung tumour. • Malignancy can be determined on a post-RFA biopsy in 90 % of cases. • Cancer classification can be assessed in 70 % of cases after lung RFA.

  15. High single-pass diagnostic yield of a new 25-gauge core biopsy needle for EUS-guided FNA biopsy in solid pancreatic lesions.

    PubMed

    Iwashita, Takuji; Nakai, Yousuke; Samarasena, Jason B; Park, Do Hyun; Zhang, Zesong; Gu, Mai; Lee, John G; Chang, Kenneth J

    2013-06-01

    Current limitations of EUS-guided FNA include the need for multiple passes and on-site cytology assessment and lack of core specimen. Recently, a new 25-gauge core biopsy needle (PC25) was developed to overcome these limitations. To determine the diagnostic yield of EUS-guided FNA aspiration biopsy (FNAB) when using the PC25 needle among patients with solid pancreatic lesions. Retrospective analysis. Academic tertiary referral center. Fifty consecutive patients with a solid pancreatic lesion underwent EUS-guided FNAB with PC25. EUS-guided FNAB with PC25. The primary outcome was the diagnostic yield in single and overall passes of EUS-guided FNAB when using the PC25 needle for pancreatic solid lesions. Cytologic analysis showed malignancy in 38 patients on the first pass, with a cumulative sensitivity of 83%, 91%, and 96% on passes 1, 2, and 3, respectively. Although visible core was reported in 46 patients (92%), histologic core was seen in 16 patients (32%). Histologic analysis showed malignancy in 29 patients on the first pass, with a cumulative sensitivity of 63% and 87% on pass 1 and passes 1 to 4, respectively. The sensitivity, specificity, and accuracy in combined cytologic and histologic results were 85%, 100%, and 86% for single pass and 96%, 100%, and 96% on multiple passes, respectively. No complications were seen. A retrospective study design at a single center using a single arm. EUS-guided FNAB with the PC25 needle showed excellent single-pass and overall diagnostic yields. This needle appears to maintain a high cytologic yield, similar to standard 25-gauge FNA needles, while also providing some histologic core tissue. Copyright © 2013 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.

  16. Diagnostic cellular yield is superior with full pars plana vitrectomy compared with core vitreous biopsy.

    PubMed

    Mudhar, H S; Sheard, R

    2013-01-01

    Vitreous biopsy for the cytological assessment of suspected intraocular lymphoma and vitritis of uncertain aetiology is a standard investigation. The types of specimens generated and the diagnostic rate are variable within and between centres. There are many reasons for this but one observation that has not been considered previously is the differential distribution of cells in the vitreous gel. To test this possibility, five consecutive patients with suspected vitreous involvement by lymphoma or vitritis of uncertain aetiology underwent a core vitreous biopsy immediately before a planned full pars plana vitrectomy (PPV) and the cellularity of the two sampling techniques compared. A prospective study of five consecutive patients requiring vitreous sampling to secure a firm diagnosis. For each of five patients, the core vitreous biopsy specimen was received in a universal tube and the PPV specimen was received in a vitreous cassette. Fluid (0.25 ml) was removed from both specimens, centrifuged and haematoxylin and eosin (H&E) stained slides prepared per sampling method. The slides were examined with a light microscope, the most cellular field selected and the number of cells per mm(2) counted and compared between sampling techniques. PPV specimen's, revealed a cellularity range that was 7.4 to 78 × (average 31 ×) greater than a core vitreous biopsy. In the two cases of a final diagnosis of intraocular lymphoma, the vitreous core biopsy was non-diagnostic. Furthermore, the PPV specimen generated additional cellular material for numerous ancillary investigations to permit a secure diagnosis. The results of this differential vitreous sampling study has strengthened our anecdotal slit lamp clinical observations that inflammatory cells and lymphoma cells are concentrated more in the cortical vitreous. Therefore, vitreous cells have less chance to be sampled if a single core vitreous biopsy is performed. Indeed, the two cases of confirmed lymphoma generated a non

  17. Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis

    PubMed Central

    Joo, Eun-Jeong; Yeom, Joon-Sup; Ha, Young Eun; Park, So Yeon; Lee, Chong-Suh; Kim, Eun-Sang; Kang, Cheol-In; Chung, Doo-Ryeon; Song, Jae-Hoon; Peck, Kyong Ran

    2016-01-01

    Background/Aims: This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections. Methods: The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years. Results: Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026). Conclusions: Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery. PMID:27079327

  18. Diagnostic yield of computed tomography-guided bone biopsy and clinical outcomes of tuberculous and pyogenic spondylitis.

    PubMed

    Joo, Eun-Jeong; Yeom, Joon-Sup; Ha, Young Eun; Park, So Yeon; Lee, Chong-Suh; Kim, Eun-Sang; Kang, Cheol-In; Chung, Doo-Ryeon; Song, Jae-Hoon; Peck, Kyong Ran

    2016-07-01

    This study aimed to evaluate the efficacy of computed tomography (CT)-guided bone biopsy for the diagnosis of spinal infection and compared the clinical outcomes between tuberculous and pyogenic spinal infections. The retrospective cohort study included patients who received CT-guided bone biopsy at a tertiary hospital over the 13 years. Among 100 patients, 67 had pyogenic spondylitis and 33 had tuberculous spondylitis. Pathogens were isolated from bone specimens obtained by CT-guided biopsy in 42 cases, with diagnostic yields of 61% (20/33) for tuberculous spondylitis and 33% (22/67) for pyogenic spondylitis. For 36 culture-proven pyogenic cases, Staphylococcus aureus was the most commonly isolated organism. Patients with pyogenic spondylitis more frequently presented with fever accompanied by an increase in inflammatory markers than did those with tuberculosis. Among all patients who underwent surgery, the incidence of late surgery performed one month after diagnosis was higher in patients with tuberculous infection (56.3%) than in those with pyogenic disease (23.3%, p = 0.026). Results obtained by CT-guided bone biopsy contributed to prompt diagnoses of spinal infections, especially those caused by tuberculosis. Despite administration of anti-tuberculous agents, patients with tuberculous spondylitis showed an increased tendency to undergo late surgery.

  19. Charlie's Clamp.

    ERIC Educational Resources Information Center

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  20. Rotary powered device for bone marrow aspiration and biopsy yields excellent specimens quickly and efficiently.

    PubMed

    Swords, Ronan T; Kelly, Kevin R; Cohen, Stephen C; Miller, Larry J; Philbeck, Thomas E; Hacker, Sander O; Spadaccini, Cathy J; Giles, Francis J; Brenner, Andrew J

    2010-06-01

    Recently, a new FDA-cleared battery powered bone marrow biopsy system was developed to allow operators access to the bone marrow space quickly and efficiently. A pre-clinical evaluation of the device (OnControl, Vidacare Corporation, San Antonio, TX, USA) on anesthetized pigs was conducted, in addition to a clinical evaluation in hematology clinic patients requiring a bone marrow biopsy. Twenty-six samples were collected from the swine model. No cellular artifact or thermal damage was reported in any of the samples obtained. For the clinical evaluation of the device, 16 patients were recruited. Mean time from needle contact with skin to needle removal was 38.5 +/- 13.94 seconds. No complications were reported. In this study, the manual and powered samples were equivalent in specimen quality. In the patients evaluated, the device was safe, easy to use and the mean procedural time was significantly faster than previously reported with a manual technique.

  1. Feasibility and Diagnostic Yield of Endoscopic Ultrasonography-Guided Fine Needle Biopsy With a New Core Biopsy Needle Device in Patients With Gastric Subepithelial Tumors

    PubMed Central

    Lee, Minju; Min, Byung-Hoon; Lee, Hyuk; Ahn, Sangjeong; Lee, Jun Haeng; Rhee, Poong-Lyul; Kim, Jae J.; Sohn, Tae Sung; Kim, Sung; Kim, Kyoung-Mee

    2015-01-01

    Abstract As treatment decisions for patients with gastric subepithelial tumors (SETs) largely depend on the histopathologic diagnosis, noninvasive and effective tissue acquisition methods are definitely required for proper management of gastric SETs. Recently, a new endoscopic ultrasonography-guided fine needle biopsy (EUS-FNB) device with ProCore reverse bevel technology was developed. We aimed to elucidate the feasibility and diagnostic yield of EUS-FNB with this new core biopsy needle device in patients with gastric SETs. A prospectively maintained database was retrospectively reviewed to identify consecutive patients who underwent EUS-FNB with a 22-gauge ProCore needle for gastric SETs 2 cm or larger. The main outcome measurement was the diagnostic yield of EUS-FNB. Procedure results were categorized into diagnostic, suggestive, or nondiagnostic. Of the 43 patients, needle punctures were successful in all cases irrespective of tumor location. EUS-FNB procedure results were diagnostic in 86.0%, suggestive in 4.7%, and nondiagnostic in 9.3% of cases, respectively. The diagnostic yield was the highest in fundus (100.0%), followed by body (89.5%), cardia (83.3%), and antrum (50.0%). All 18 patients with cardiac SET were finally diagnosed to have leiomyoma, and 16 patients with diagnostic or suggestive results avoided surgery. A heterogeneous echo pattern on EUS was found in 33.3% of cases with nondiagnostic or suggestive results and in 5.4% with diagnostic results. In multivariate analysis, no independent predictor of unsuccessful EUS-FNB with nondiagnostic or suggestive results was identified. Agreement between EUS-FNB and surgical pathology was 100% with respect to the diagnosis of gastrointestinal stromal tumor. However, there was a significant discrepancy in mitotic counts observed between the EUS-FNB and surgical specimens in patients with gastrointestinal stromal tumor. There were no significant procedure-related adverse events during and after the

  2. Feasibility and Diagnostic Yield of Endoscopic Ultrasonography-Guided Fine Needle Biopsy With a New Core Biopsy Needle Device in Patients With Gastric Subepithelial Tumors.

    PubMed

    Lee, Minju; Min, Byung-Hoon; Lee, Hyuk; Ahn, Sangjeong; Lee, Jun Haeng; Rhee, Poong-Lyul; Kim, Jae J; Sohn, Tae Sung; Kim, Sung; Kim, Kyoung-Mee

    2015-10-01

    As treatment decisions for patients with gastric subepithelial tumors (SETs) largely depend on the histopathologic diagnosis, noninvasive and effective tissue acquisition methods are definitely required for proper management of gastric SETs. Recently, a new endoscopic ultrasonography-guided fine needle biopsy (EUS-FNB) device with ProCore reverse bevel technology was developed. We aimed to elucidate the feasibility and diagnostic yield of EUS-FNB with this new core biopsy needle device in patients with gastric SETs. A prospectively maintained database was retrospectively reviewed to identify consecutive patients who underwent EUS-FNB with a 22-gauge ProCore needle for gastric SETs 2 cm or larger. The main outcome measurement was the diagnostic yield of EUS-FNB. Procedure results were categorized into diagnostic, suggestive, or nondiagnostic. Of the 43 patients, needle punctures were successful in all cases irrespective of tumor location. EUS-FNB procedure results were diagnostic in 86.0%, suggestive in 4.7%, and nondiagnostic in 9.3% of cases, respectively. The diagnostic yield was the highest in fundus (100.0%), followed by body (89.5%), cardia (83.3%), and antrum (50.0%). All 18 patients with cardiac SET were finally diagnosed to have leiomyoma, and 16 patients with diagnostic or suggestive results avoided surgery. A heterogeneous echo pattern on EUS was found in 33.3% of cases with nondiagnostic or suggestive results and in 5.4% with diagnostic results. In multivariate analysis, no independent predictor of unsuccessful EUS-FNB with nondiagnostic or suggestive results was identified. Agreement between EUS-FNB and surgical pathology was 100% with respect to the diagnosis of gastrointestinal stromal tumor. However, there was a significant discrepancy in mitotic counts observed between the EUS-FNB and surgical specimens in patients with gastrointestinal stromal tumor. There were no significant procedure-related adverse events during and after the procedures. EUS

  3. Vortex-dislodged cells from bone marrow trephine biopsy yield satisfactory results for flow cytometric immunophenotyping.

    PubMed

    Bommannan, K; Sachdeva, M U S; Gupta, M; Bose, P; Kumar, N; Sharma, P; Naseem, S; Ahluwalia, J; Das, R; Varma, N

    2016-10-01

    A good bone marrow (BM) sample is essential in evaluating many hematologic disorders. An unsuccessful BM aspiration (BMA) procedure precludes a successful flow cytometric immunophenotyping (FCI) in most hematologic malignancies. Apart from FCI, most ancillary diagnostic techniques in hematology are less informative. We describe the feasibility of FCI in vortex-dislodged cell preparation obtained from unfixed trephine biopsy (TB) specimens. In pancytopenic patients and dry tap cases, routine diagnostic BMA and TB samples were complemented by additional trephine biopsies. These supplementary cores were immediately transferred into sterile tubes filled with phosphate-buffered saline, vortexed, and centrifuged. The cell pellet obtained was used for flow cytometric immunophenotyping. Of 7955 BMAs performed in 42 months, 34 dry tap cases were eligible for the study. Vortexing rendered a cell pellet in 94% of the cases (32 of 34), and FCI rendered a rapid diagnosis in 100% of the cases (32 of 32) where cell pellets were available. We describe an efficient procedure which could be effectively utilized in resource-limited centers and reduce the frequency of repeat BMA procedures. © 2016 John Wiley & Sons Ltd.

  4. Diagnostic yield of endoscopic ultrasonography-guided single-incision needle knife biopsy for gastric subepithelial tumors: comparison with resected specimens.

    PubMed

    Kim, Joon Sung; Kim, Byung-Wook; Kim, Gi Jun; Kim, Young Wook; Ryu, Seung Ji; Park, Sung Min; Ji, Jeong-Seon; Jun, Sun Young

    2016-12-01

    Several techniques are recommended for the histologic diagnosis of gastric subepithelial tumors (SETs). The purpose of our study was to evaluate the diagnostic yield and safety of endoscopic ultrasonography-guided single-incision needle knife (SINK) biopsy for the diagnosis of gastric SETs. A retrospective review of patients who received biopsy for gastric SETs from August 2012 to May 2015 was conducted. Patients who received endoscopic ultrasonography and were found to have a SET originating from the muscularis propria of the stomach were included in the study. The aim of our study was to investigate the safety and diagnostic yield of SINK biopsy for gastric SETs. A total of 31 patients received SINK biopsy for SETs. The diagnostic yield of SINK biopsy was 87 % (95 % CI 75-100 %), and the diagnostic accuracy was 89 % (95 % CI 74-105 %). The sensitivity of SINK biopsy to identify gastrointestinal stromal tumors was 83 % (95 % CI 52-98 %); the specificity was 100 % (95 % CI 59-100 %); the positive predictive value was 100 % (95 % CI 69-100 %); and the negative predictive value was 78 % (95 % CI 40-97 %). There were no procedure-related adverse events during and after procedure. The use of SINK biopsy technique in patients with SETs is a good diagnostic tool with high diagnostic yield and accuracy. The method is simple, safe, and associated with few complications.

  5. Factors influencing the diagnostic yield and accuracy of image-guided percutaneous needle biopsy of pediatric tumors: single-center audit of a 26-year experience.

    PubMed

    Blondiaux, Eléonore; Laurent, Méryle; Audureau, Etienne; Boudjemaa, Sabah; Sileo, Chiara; Lenoir, Marion; Dainese, Linda; Garel, Catherine; Coulomb, Aurore; Ducou le Pointe, Hubert

    2016-03-01

    Image-guided percutaneous core needle biopsy is a common procedure for diagnosis of both solid tumors and hematological malignancies in children. Despite recent improvements, a certain rate of non-diagnostic biopsies persists. To assess the factors influencing the diagnostic yield and accuracy of percutaneous core needle biopsies of pediatric tumors. We conducted a single-center retrospective study of a 26-year experience with image-guided biopsies in children and young adults. Using uni- and multivariate analysis, we evaluated the association of diagnostic yield and accuracy with technical factors (image-guided procedure, pathological technique) and clinical factors (complication rate, histological type and anatomical location). We retrieved data relating to 396 biopsies were performed in 363 children and young adults (mean age: 7.4 years). Overall, percutaneous core needle biopsy showed a diagnostic yield of 89.4% (95% confidence interval [CI] 85.9-92.2) and an accuracy of 90.9% (CI 87.6-93.6) with a complication rate of 2.5% (CI 1.2-4.6).The diagnostic yield increased with the use of advanced tissue assessment techniques (95.7% with immunohistochemistry versus 82.3% without immunohistochemistry; P < 0.0001) and an increased number of passes (mean: 3.96 for diagnostic biopsies versus 3.62 for non-diagnostic biopsies; P = 0.044). The use of advanced pathological techniques and an increased number of passes are the two main factors influencing the diagnostic success of biopsies in pediatric tumors.

  6. Do the number and volume of surgical lung biopsies influence the diagnostic yield in interstitial lung disease? A propensity score analysis.

    PubMed

    Fibla, Juan J; Brunelli, Alessandro; Allen, Mark S; Wigle, Dennis; Shen, Robert; Nichols, Francis; Deschamps, Claude; Cassivi, Stephen D

    2015-02-01

    Our objective was to evaluate whether the number and volume of surgical lung biopsies (SLB) influence the diagnosis of diffuse interstitial lung disease (ILD). Retrospective study of SLB for suspected ILD in patients from the Mayo Clinic from January 2002 to January 2010. Data were collected in the institution and analyzed. 311 patients were studied. Mean number of biopsies was 2.05 (SD 0.6); 1 biopsy in 50 (16%), 2 in 198 (63.7%), 3 in 59 (19%) and 4 in 4 (1.3%). Histopathologic diagnosis was: definitive (specific): 232 (74.6%), descriptive (non-specific): 76 (24.4%), no diagnosis: 3 (1%). After excluding patients without diagnosis (n=3), there were 50 patients with only 1 biopsy, 196 with 2 and 62 with 3 or 4; the definitive diagnostic yield was similar in all 3 groups (37/50; 74%, 150/196; 77%, and 45/62; 73%) (Chi-square, p value 0.8). The propensity score analysis between patients with 1 SLB and patients with more than 1 SLB also showed no difference in diagnostic yield. Regarding the volume of biopsies, mean total volume was 34.4 cm(3) (SD 46): 41.2 cm(3) (3 cases) in patients with no diagnosis; 33.6 cm(3) (232 cases, SD 47) in patients with specific diagnosis; and 36.6 cm(3) (76 cases, SD 44) in patients with descriptive diagnosis. Biopsy volume had no influence on histopathology yield (ANOVA, p value .8). The number and volume of the biopsy specimens in SLB did not seem to influence diagnosis. Based on our results, we believe a single sample from a representative area may be sufficient for diagnosis. Randomized prospective trials should be performed to optimize SLB for ILD. Copyright © 2014 SEPAR. Published by Elsevier Espana. All rights reserved.

  7. Clamp usable as jig and lifting clamp

    DOEpatents

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  8. Endobronchial Ultrasound-guided Transbronchial Needle Aspiration Increases the Yield of Transbronchial Lung Biopsy for the Evaluation of Peribronchial Lesions

    PubMed Central

    Chen, Cheng; Mu, Chuan-Yong; Su, Mei-Qin; Mao, Jing-Yu; Zhu, Ye-Han; Huang, Jian-An

    2017-01-01

    Background: Due to absence of visible endobronchial target, the diagnostic yield of flexible bronchoscopy for peribronchial lesions has been unsatisfactory. Convex probe endobronchial ultrasound (CP-EBUS) has allowed for performing real-time transbronchial needle aspiration (TBNA) of enlarged hilar and mediastinal lymph nodes and therefore could also be used as a means of diagnosing proximal peribronchial lesions. Methods: We retrospectively analyzed the results related to 72 patients who underwent CP-EBUS for peribronchial lesions without endobronchial involvement and adjacent to three-grade bronchi based on chest computed tomography (CT) scan. We recorded the images during EBUS as well as the diagnostic results of TBNA and conventional-transbronchial lung biopsy/brush (C-TBLB/b), and final diagnoses were based on pathologic analysis and follow-up. Results: In all cases, the mass was able to be identified using EBUS in 97.2% patients (70/72) who were performed with EBUS-TBNA + C-TBLB/b. Sixty-six patients had a final diagnosis, 80.0% patients (56/70) had malignancies, and 14.3% patients (10/70) had benign disease. In malignancies, the diagnostic yield of C-TBLB/b was 57.1% (32/56) and in EBUS-TBNA was 85.7% (48/56), whereas pathologic diagnosis reached 94.6% when EBUS-TBNA was combined with C-TBLB/b. C-TBLB/b + EBUS-TBNA also exhibited stronger potency of histolytic diagnosis for malignancies than either EBUS-TBNA or C-TBLB/b alone. Furthermore, there are data supporting the value of EBUS-TBNA for the diagnosis of benign lung disease. Conclusion: The combined endoscopic approach with EBUS-TBNA and C-TBLB/b is an accurate and effective method for the evaluation of peribronchial lesions, with better results than using each technique alone. PMID:28051017

  9. Diagnostic Yield of Computed Tomography-Guided Coaxial Core Biopsy of Undetermined Masses in the Free Retroperitoneal Space: Single-Center Experience

    SciTech Connect

    Stattaus, Joerg Kalkmann, Janine Kuehl, Hilmar; Metz, Klaus A.; Nowrousian, Mohammad R.; Forsting, Michael Ladd, Susanne C.

    2008-09-15

    The purpose of this study was to evaluate the diagnostic yield of core biopsy in coaxial technique under guidance of computed tomography (CT) for retroperitoneal masses. We performed a retrospective analysis of CT-guided coaxial core biopsies of undetermined masses in the non-organ-bound retroperitoneal space in 49 patients. In 37 cases a 15-G guidance needle with a 16-G semiautomated core biopsy system, and in 12 cases a 16-G guidance needle with an 18-G biopsy system, was used. All biopsies were technically successful. A small hematoma was seen in one case, but no relevant complication occurred. With the coaxial technique, up to 4 specimens were obtained from each lesion (mean, 2.8). Diagnostic accuracy in differentiation between malignant and benign diseases was 95.9%. A specific histological diagnosis could be established in 39 of 42 malignant lesions (92.9%). Correct subtyping of malignant lymphoma according to the WHO classification was possible in 87.0%. Benign lesions were correctly identified in seven cases, although a specific diagnosis could only be made in conjunction with clinical and radiological information. In conclusion, CT-guided coaxial core biopsy provides safe and accurate diagnosis of retroperitoneal masses. A specific histological diagnosis, which is essential for choosing the appropriate therapy, could be established in most cases of malignancy.

  10. CT fluoroscopy-guided renal tumour cutting needle biopsy: retrospective evaluation of diagnostic yield, safety, and risk factors for diagnostic failure.

    PubMed

    Iguchi, Toshihiro; Hiraki, Takao; Matsui, Yusuke; Fujiwara, Hiroyasu; Sakurai, Jun; Masaoka, Yoshihisa; Gobara, Hideo; Kanazawa, Susumu

    2017-08-02

    To evaluate retrospectively the diagnostic yield, safety, and risk factors for diagnostic failure of computed tomography (CT) fluoroscopy-guided renal tumour biopsy. Biopsies were performed for 208 tumours (mean diameter 2.3 cm; median diameter 2.1 cm; range 0.9-8.5 cm) in 199 patients. One hundred and ninety-nine tumours were ≤4 cm. All 208 initial procedures were divided into diagnostic success and failure groups. Multiple variables related to the patients, lesions, and procedures were assessed to determine the risk factors for diagnostic failure. After performing 208 initial and nine repeat biopsies, 180 malignancies and 15 benign tumours were pathologically diagnosed, whereas 13 were not diagnosed. In 117 procedures, 118 Grade I and one Grade IIIa adverse events (AEs) occurred. Neither Grade ≥IIIb AEs nor tumour seeding were observed within a median follow-up period of 13.7 months. Logistic regression analysis revealed only small tumour size (≤1.5 cm; odds ratio 3.750; 95% confidence interval 1.362-10.326; P = 0.011) to be a significant risk factor for diagnostic failure. CT fluoroscopy-guided renal tumour biopsy is a safe procedure with a high diagnostic yield. A small tumour size (≤1.5 cm) is a significant risk factor for diagnostic failure. • CT fluoroscopy-guided renal tumour biopsy has a high diagnostic yield. • CT fluoroscopy-guided renal tumour biopsy is safe. • Small tumour size (≤1.5 cm) is a risk factor for diagnostic failure.

  11. Force-Measuring Clamps

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark

    2003-01-01

    Force-measuring clamps have been invented to facilitate and simplify the task of measuring the forces or pressures applied to clamped parts. There is a critical need to measure clamping forces or pressures in some applications for example, while bonding sensors to substrates or while clamping any sensitive or delicate parts. Many manufacturers of adhesives and sensors recommend clamping at specific pressures while bonding sensors or during adhesive bonding between parts in general. In the absence of a force-measuring clamp, measurement of clamping force can be cumbersome at best because of the need for additional load sensors and load-indicating equipment. One prior method of measuring clamping force involved the use of load washers or miniature load cells in combination with external power sources and load-indicating equipment. Calibrated spring clamps have also been used. Load washers and miniature load cells constitute additional clamped parts in load paths and can add to the destabilizing effects of loading mechanisms. Spring clamps can lose calibration quickly through weakening of the springs and are limited to the maximum forces that the springs can apply. The basic principle of a force-measuring clamp can be implemented on a clamp of almost any size and can enable measurement of a force of almost any magnitude. No external equipment is needed because the component(s) for transducing the clamping force and the circuitry for supplying power, conditioning the output of the transducers, and displaying the measurement value are all housed on the clamp. In other words, a force-measuring clamp is a complete force-application and force-measurement system all in one package. The advantage of unitary packaging of such a system is that it becomes possible to apply the desired clamping force or pressure with precision and ease.

  12. Microbiology specimens obtained at the time of surgical lung biopsy for interstitial lung disease: clinical yield and cost analysis.

    PubMed

    Fibla, Juan J; Brunelli, Alessandro; Allen, Mark S; Wigle, Dennis; Shen, Robert; Nichols, Francis; Deschamps, Claude; Cassivi, Stephen D

    2012-01-01

    In efforts to obtain complete results, current practice in surgical lung biopsy (LB) for interstitial lung disease (ILD) recommends sending lung tissue samples for bacterial, mycobacterial, fungal, and viral cultures. This study assesses the value of this practice by evaluating the microbiology findings obtained from LB for ILD and their associated costs. A total of 296 consecutive patients (140 women, 156 men, median age=61 years) underwent LB for ILD from 2002 to 2009. All had lung tissue sent for microbiology examination. Microbiology results and resultant changes in patient management were analyzed retrospectively. A cost analysis was performed based upon nominal hospital charges adjusted on current inflation rates. Cost data included cultures, stains, smears, direct fluorescent antibody studies, and microbiologist consulting fees. As many as 25 patients (8.4%) underwent open LB and 271 (91.6%) underwent thoracoscopic LB. A total of 592 specimens were assessed (range 1-4 per patient). The most common pathologic diagnoses were idiopathic pulmonary fibrosis in 122 (41.2%), cryptogenic organizing pneumonia in 31 (10.5%), and respiratory bronchiolitis ILD in 16 (5.4%). Microbiology testing was negative in 174 patients (58.8%). A total of 118 of 122 (96.7%) positive results were clinically considered to be contaminants and resulted in no change in clinical management. The most common contaminants were Propionibacterium acnes (38 patients; 31%) and Penicillium fungus (16 patients; 13%). In only four patients (1.4%), the organism cultured (Nocardia one, Histoplasma one, and Aspergillus fumigatus two) resulted in a change in clinical management. The cost of microbiology studies per specimen was $984 (€709), with a total cost for the study cohort being $582,000 (€420,000). The yield and impact on clinical management of microbiology specimens from LB for ILD is very low. Its routine use in LB is questionable. We suggest it should be limited to those cases of ILD with

  13. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  14. Force-Measuring Clamp

    NASA Technical Reports Server (NTRS)

    Nunnelee, Mark (Inventor)

    2004-01-01

    A precision clamp that accurately measures force over a wide range of conditions is described. Using a full bridge or other strain gage configuration. the elastic deformation of the clamp is measured or detected by the strain gages. Thc strain gages transmit a signal that corresponds to the degree of stress upon the clamp. Thc strain gage signal is converted to a numeric display. Calibration is achieved by ero and span potentiometers which enable accurate measurements by the force-measuring clamp.

  15. Photovoltaic panel clamp

    SciTech Connect

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  16. Photovoltaic panel clamp

    SciTech Connect

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  17. Clamping in Boltzmann machines.

    PubMed

    Livesey, M

    1991-01-01

    A certain assumption that appears in the proof of correctness of the standard Boltzmann machine learning procedure is investigated. The assumption, called the clamping assumption, concerns the behavior of a Boltzmann machine when some of its units are clamped to a fixed state. It is argued that the clamping assumption is essentially an assertion of the time reversibility of a certain Markov chain underlying the behavior of the Boltzmann machine. As such, the clamping assumption is generally false, though it is certainly true of the Boltzmann machines themselves. The author also considers how the concept of the Boltzmann machine may be generalized while retaining the validity of the clamping assumption.

  18. Radial wedge flange clamp

    DOEpatents

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  19. Diagnostic Yield and Complications Using a 20 Gauge Prostate Biopsy Needle versus a Standard 18 Gauge Needle: A Randomized Controlled Study.

    PubMed

    Wang, Jianlong; Wan, Ben; Li, Chao; Wang, Jianye; Fu, Qiang; Zhao, Weixin; Zhang, Kaile

    2015-11-14

    To compare and evaluate whether a 20 gauge (20G) biopsy needle maintains a similar detection rate as that of the commonly used 18G needle for transrectal ultrasound-guided prostate biopsy (TRUSPB) aimed at assessing prostate cancer (PCa) and decreasing pain and complications. A total of 122 cases with indications of PCa were randomly allocated into two groups for this randomized controlled study. TRUSPB was performed randomly using either an 18G or 20G needle for core biopsies (62 cases with 18G and 60 cases with 20G). Detection rate, pain, and complications were assessed after the procedure. The cancer detection rate in the 18G group (40.3%) did not differ from that in the 20G group (35.0%). However, the number of patients with pain was significantly lower in 20G group (P < 0.05). The number of patients with self-limiting hematuria decreased in both groups after the biopsy procedure (18G: 38 cases; 20G: 16 cases; P < .0001). Hematochezia occurred in 11 cases (9 cases [14.5%] in the 18G group; 2 cases [3.4%] in the 20G group). The number of patients with infection, dysuria, and urinary retention tended to be lower in 20G group. Use of a 20G needle for TRUSPB yielded a comparable cancer detection rate to that of an 18G needle and led to less local injury, pain, and complications. A larger and more sensitive study is needed to verify our results.

  20. Quick action clamp

    NASA Technical Reports Server (NTRS)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  1. Small Musculoskeletal Soft-Tissue Lesions: US-guided Core Needle Biopsy--Comparative Study of Diagnostic Yields according to Lesion Size.

    PubMed

    Kim, Sang Yoon; Chung, Hye Won

    2016-01-01

    To determine the effectiveness of ultrasonographically (US) guided core needle biopsy (CNB) for diagnosis of small musculoskeletal soft-tissue lesions by demonstrating the noninferiority of the diagnostic yield with US-guided CNB in lesions measuring 2 cm or smaller to that for lesions larger than 2 cm. This retrospective study was institutional review board approved, and the requirement to obtain informed consent was waived. Five hundred US-guided CNBs performed for diagnosis of musculoskeletal soft-tissue lesions were included. Results of US-guided CNBs were divided into four categories, and the diagnostic yields were calculated on the basis of lesion size. A one-sided 97.5% confidence interval was calculated to determine the mean difference in diagnostic yields to test for noninferiority. In addition, the diagnostic yield with US-guided CNBs for lesions 1 cm or smaller was compared with that for lesions larger than 1 cm. A total of 500 technically successful US-guided CNBs in 494 patients with musculoskeletal soft-tissue lesions who underwent subsequent surgical excision or at least 6 months of follow-up were included. The diagnostic yields with US-guided CNB were 87% for lesions larger than 2 cm and 88% for lesions 2 cm or smaller. The lower bound of the confidence interval was -0.07, thus the noninferiority of the diagnostic yield with CNB for lesions 2 cm or smaller to that for lesions larger than 2 cm was shown. On the other hand, the diagnostic yield with US-guided CNB for lesions 1 cm or smaller was inferior to that for lesions larger than 1 cm. US-guided CNB of musculoskeletal soft-tissue lesions is effective for diagnosis and decision making, even in lesions measuring 2 cm or smaller. However, when a lesion is 1 cm or smaller, US-guided CNB is more frequently insufficient for histopathologic diagnosis. © RSNA, 2015.

  2. Prostate biopsy

    MedlinePlus

    ... prostate biopsy; Fine needle biopsy of the prostate; Core biopsy of the prostate; Targeted prostate biopsy; Prostate ... to the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein ...

  3. A monogenean without clamps

    USDA-ARS?s Scientific Manuscript database

    Ectoparasites face a daily challenge: to remain attached to their host. Polyopisthocotylean monogeneans attach to the surface of fish gills by highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 50 years...

  4. Laser beam guard clamps

    DOEpatents

    Dickson, Richard K.

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  5. Sperm Patch-Clamp

    PubMed Central

    Lishko, Polina; Clapham, David E.; Navarro, Betsy; Kirichok, Yuriy

    2014-01-01

    Sperm intracellular pH and calcium concentration ([Ca2+]i) are two central factors that control sperm activity within the female reproductive tract. As such, the ion channels of the sperm plasma membrane that alter intracellular sperm [Ca2+] and pH play important roles in sperm physiology and the process of fertilization. Indeed, sperm ion channels regulate sperm motility, control sperm chemotaxis toward the egg in some species, and may trigger the acrosome reaction. Until recently, our understanding of these important molecules was rudimentary due to the inability to patch-clamp spermatozoa and directly record the activity of these ion channels under voltage clamp. Recently, we overcame this technical barrier and developed a method for reproducible application of the patch-clamp technique to mouse and human spermatozoa. This chapter covers important aspects of application of the patch-clamp technique to spermatozoa, such as selection of the electrophysiological equipment, isolation of spermatozoa for patch-clamp experiments, formation of the gigaohm seal with spermatozoa, and transition into the whole-cell mode of recording. We also discuss potential pitfalls in application of the patch-clamp technique to flagellar ion channels. PMID:23522465

  6. Assessment of Factors Affecting the Usefulness and Diagnostic Yield of Core Biopsy Needles with a Side Hole in Endoscopic Ultrasound-Guided Fine-Needle Aspiration

    PubMed Central

    Inoue, Tadahisa; Okumura, Fumihiro; Mizushima, Takashi; Nishie, Hirotada; Iwasaki, Hiroyasu; Anbe, Kaiki; Ozeki, Takanori; Kachi, Kenta; Fukusada, Shigeki; Suzuki, Yuta; Sano, Hitoshi

    2016-01-01

    Background/Aims A barbed puncture needle with a side hole was recently developed to improve sample quality and quantity in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). In this study, we retrospectively assessed the usefulness of this puncture needle. Methods Factors affecting diagnostic yield, safety, and diagnostic accuracy were investigated in 76 patients who consecutively underwent EUS-FNA for neoplastic lesions at our hospital between January and December 2013. Results The procedure was successful in all cases; the rates of sample collection and determination of the correct diagnosis were 92.1% and 89.5%, respectively. The mean number of needle passes required for diagnosis was 1.1. Complications included mild intraluminal bleeding in two patients (2.6%). Multivariate analysis revealed that lesion size (≤20 mm) was significantly associated with a decreased chance of determining the correct diagnosis. Conclusions Core biopsy needles with a side hole are safe and provide a satisfactory diagnostic yield. However, the side hole may potentially reduce the rate of making the correct diagnosis in small lesions. PMID:25963081

  7. Assessment of Factors Affecting the Usefulness and Diagnostic Yield of Core Biopsy Needles with a Side Hole in Endoscopic Ultrasound-Guided Fine-Needle Aspiration.

    PubMed

    Inoue, Tadahisa; Okumura, Fumihiro; Mizushima, Takashi; Nishie, Hirotada; Iwasaki, Hiroyasu; Anbe, Kaiki; Ozeki, Takanori; Kachi, Kenta; Fukusada, Shigeki; Suzuki, Yuta; Sano, Hitoshi

    2016-01-01

    A barbed puncture needle with a side hole was recently developed to improve sample quality and quantity in endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). In this study, we retrospectively assessed the usefulness of this puncture needle. Factors affecting diagnostic yield, safety, and diagnostic accuracy were investigated in 76 patients who consecutively underwent EUS-FNA for neoplastic lesions at our hospital between January and December 2013. The procedure was successful in all cases; the rates of sample collection and determination of the correct diagnosis were 92.1% and 89.5%, respectively. The mean number of needle passes required for diagnosis was 1.1. Complications included mild intraluminal bleeding in two patients (2.6%). Multivariate analysis revealed that lesion size (≤20 mm) was significantly associated with a decreased chance of determining the correct diagnosis. Core biopsy needles with a side hole are safe and provide a satisfactory diagnostic yield. However, the side hole may potentially reduce the rate of making the correct diagnosis in small lesions.

  8. Standards for prostate biopsy

    PubMed Central

    Bjurlin, Marc A.; Taneja, Samir S.

    2014-01-01

    Purpose of review A variety techniques have emerged for optimization of prostate biopsy. In this review, we summarize and critically discuss the most recent developments regarding the optimal systematic biopsy and sampling labeling along with multiparametric MRI and MR targeted biopsies. Recent findings The use of 10–12-core extended-sampling protocols increases cancer detection rates compared to traditional sextant sampling and reduces the likelihood that patients will require a repeat biopsy, ultimately allowing more accurate risk stratification without increasing the likelihood of detecting insignificant cancers. As the number of cores increases above 12 cores, the increase in diagnostic yield becomes marginal. However, limitations of this technique include undersampling, over-sampling, and the need for repetitive biopsy. MRI and MR-targeted biopsies have demonstrated superiority over systematic biopsies for the detection of clinically significant disease and representation of disease burden, while deploying fewer cores and may have applications in men undergoing initial or repeat biopsy and those with low risk cancer on or considering active surveillance. Summary A 12-core systematic biopsy that incorporates apical and far-lateral cores in the template distribution allows maximal cancer detection, avoidance of a repeat biopsy, while minimizing the detection of insignificant prostate cancers. MRI guided prostate biopsy has an evolving role in both initial and repeat prostate biopsy strategies, as well as active surveillance, potentially improving sampling efficiency, increasing detection of clinically significant cancers, and reducing detection of insignificant cancers. PMID:24451092

  9. Clamping characteristics study on different types of clamping unit

    SciTech Connect

    Jiao, Zhiwei; Liu, Haichao; Xie, Pengcheng; Yang, Weimin

    2015-05-22

    Plastic products are becoming more and more widely used in aerospace, IT, digital electronics and many other fields. With the development of technology, the requirement of product precision is getting higher and higher. However, type and working performance of clamping unit play a decisive role in product precision. Clamping characteristics of different types of clamping unit are discussed in this article, which use finite element numerical analysis method through the software ABAQUS to study the clamping uniformity, and detect the clamping force repeatability precision. The result shows that compared with toggled three-platen clamping unit, clamping characteristics of internal circulation two-platen clamping unit are better, for instance, its mold cavity deformation and force that bars and mold parting surface suffered are more uniform, and its clamping uniformity and repeatability precision is also better.

  10. Liver biopsy

    MedlinePlus

    Biopsy - liver; Percutaneous biopsy ... the biopsy needle to be inserted into the liver. This is often done by using ultrasound. The ... the chance of damage to the lung or liver. The needle is removed quickly. Pressure will be ...

  11. Bladder biopsy

    MedlinePlus

    Biopsy - bladder ... A bladder biopsy can be done as part of a cystoscopy . Cystoscopy is a telescopic examination of the inside of the ... informed consent form before you have a bladder biopsy. In most cases, you are asked to urinate ...

  12. Biopsy - polyps

    MedlinePlus

    Polyp biopsy ... are treated is the colon. How a polyp biopsy is done depends on the location: Colonoscopy or flexible sigmoidoscopy explores the large bowel Colposcopy-directed biopsy examines the vagina and cervix Esophagogastroduodenoscopy (EGD) or ...

  13. Kidney biopsy

    MedlinePlus

    ... may require a blood transfusion) Bleeding into the muscle, which might cause soreness Infection (small risk) Alternative Names Renal biopsy; Biopsy - kidney Images Kidney anatomy Kidney - blood and urine flow Renal biopsy References ...

  14. Clamp for detonating fuze

    NASA Technical Reports Server (NTRS)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  15. History of electrophysiology and the patch clamp.

    PubMed

    Verkhratsky, Alexei; Parpura, Vladimir

    2014-01-01

    We provide a historic outlook on the development of the concept of bioelectricity, with emphasis on the neuromuscular junction as a model that revolutionized our thinking of the nerve, nervous, and muscle tissue excitability. We abridge some crucial experiments in defining the electrical excitability of biological cells. We also provide an insight into developments of tools and methods, which gradually yielded a contemporary "palette" of electrophysiology approaches, including the patch clamp. Pioneering steps in this journey, ranging from Galvani's experiments using the Leyden jar to those of Neher and Sakmann using a gigaseal patch-clamp approach, are pictorially illustrated. This chapter is meant to be a perspective to the following sections in this volume dedicated to patch-clamp methods and protocols.

  16. Is one set of sextant biopsies enough to rule out prostate Cancer? Influence of transition and total prostate volumes on prostate cancer yield.

    PubMed

    Djavan, B; Zlotta, A R; Ekane, S; Remzi, M; Kramer, G; Roumeguère, T; Etemad, M; Wolfram, R; Schulman, C C; Marberger, M

    2000-08-01

    Although the sextant biopsy technique has been widely used, concern has arisen that this method may not include an adequate sampling of the prostate, especially for large prostate volumes. We conducted a multicenter study in patients with PSA levels <10 ng/ml to determine the influence of the total and transition zone (TZ) volumes of the prostate for predicting whether one single set of biopsies was sufficient to rule out prostate cancer (PCa). These parameters were evaluated in patients in whom PCa was found after one set of systematic sextant biopsies and those in whom PCa was found after a repeat biopsy. A total of 1,018 patients were included in this study. All underwent transrectal ultrasound-guided needle sextant and two TZ biopsies of the prostate. Total and TZ volumes of the prostate were measured (prolate ellipsoid method). From this cohort, all patients in whom a benign disease was found after the first set of biopsies underwent a second similar set of biopsies within 6 weeks. Only patients with PCa were included in this study, whether diagnosed on first or repeat biopsy. Uni- and multivariate statistical analysis using the SAS system (Cary, N.C., USA) and ROC curves were used to compare patients in whom the diagnosis was performed after the first set of biopsies and those who required a second set. Of the 1,018 patients, 344 (33.8%) had PCa diagnosed, 285 (28%) after the first set of biopsies, and 59 (8.1%) on repeat biopsy. As compared to patients diagnosed with PCa after the first set of biopsies, patients diagnosed after the second set had larger total prostate and TZ volumes (43.1+/-13.0 vs. 32.5+/-10.6 cm(3), p<0.0001 and 20.5+/-8.3 vs. 12.8+/-6.0 cm(3), p<0.0001). ROC curves showed that total and TZ volumes of 45 and 22. 5 cm(3), respectively, provided the best combination of sensitivity and specificity for discriminating between patients diagnosed with PCa after the first from those diagnosed after a second set. In patients with total prostate

  17. Core-needle biopsy under CT fluoroscopy guidance and fine-needle aspiration cytology: Comparison of diagnostic yield in the diagnosis of lung and mediastinum tumors. Analysis of frequency and types of complications.

    PubMed

    Szlęzak, Przemysław; Srutek, Ewa; Gorycki, Tomasz; Kowalewski, Janusz; Studniarek, Michał

    2014-01-01

    Patients with pathological tissue mass in thoracic cage found with imaging require histopathological or cytological confirmation of malignancy before treatment. The tissue material essential for patomorphological evaluation can be acquired with fine-needle aspiration biopsies (FNAB) controlled with CT and core-needle biopsy (CNB) under real-time CT fluoroscopy guidance. The purpose of this work is to carry out a retrospective analysis of the two methods with regards to their informativity, frequency and the kind of complications. From January, 2012 to May 2013, 76 core-needle biopsies of lung and mediastinum tumors were conducted and compared with 86 fine-needle aspiration biopsies(FNAB) of lung and mediastinum tumors, including 30 patients who underwent FNAB and were referred to CNB in order to specify the diagnosis. Complete histopathological diagnosis was made in 91% with the use of CNB and in 37% when FNAB was the chosen method. Early complications were observed in 32% patients who underwent BG and in group of 11% who underwent FNAB. Late complications, however, appeared in 29% patients after CNB and 13% after FNAB. In 24 cases CNB specified the complete diagnosis. Core-needle biopsy in comparison to fine-needle aspiration biopsy has more frequent rate of negligible complications, however, it offers higher diagnostic yield for diagnostic of lung and mediastinum neoplastic disease and allows for more precise diagnosis of focal lesions.

  18. A meta-analysis of endoscopic ultrasound–fine-needle aspiration compared to endoscopic ultrasound–fine-needle biopsy: diagnostic yield and the value of onsite cytopathological assessment

    PubMed Central

    Khan, Muhammad Ali; Grimm, Ian S.; Ali, Bilal; Nollan, Richard; Tombazzi, Claudio; Ismail, Mohammad Kashif; Baron, Todd H.

    2017-01-01

    Background The diagnostic yield of endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) is variable, and partly dependent upon rapid onsite evaluation (ROSE) by a cytopathologist. Second generation fine-needle biopsy (FNB) needles are being increasingly used to obtain core histological tissue samples. Aims Studies comparing the diagnostic yield of EUS guided FNA versus FNB have reached conflicting conclusions. We therefore conducted a systematic review and meta-analysis to compare the diagnostic yield of FNA with FNB, and specifically evaluating the diagnostic value of ROSE while comparing the two types of needles. Methods We searched several databases from inception to 10 April 2016 to identify studies comparing diagnostic yield of second generation FNB needles with standard FNA needles. Risk ratios (RR) were calculated for categorical outcomes of interest (diagnostic adequacy, diagnostic accuracy, and optimal quality histological cores obtained). Standard mean difference (SMD) was calculated for continuous variables (number of passes required for diagnosis). These were pooled using random effects model of meta-analysis to account for heterogeneity. Meta-regression was conducted to evaluate the effect of ROSE on various outcomes of interest. Results Fifteen studies with a total of 1024 patients were included in the analysis. We found no significant difference in diagnostic adequacy [RR 0.98 (0.91, 1.06), (I 2 = 51 %)]. Although not statistically significant (P = 0.06), by meta-regression, in the absence of ROSE, FNB showed a relatively better diagnostic adequacy. For solid pancreatic lesions only, there was no difference in diagnostic adequacy [RR 0.96 (0.86, 1.09), (I 2 = 66 %)]. By meta-regression, in the absence of ROSE, FNB was associated with better diagnostic adequacy (P = 0.02). There was no difference in diagnostic accuracy [RR 0.99 (0.95, 1.03), (I 2 = 27 %)] or optimal quality core histological sample

  19. Gum biopsy

    MedlinePlus

    ... be sealed off with an electric current or laser. This is called electrocauterization . After the numbness wears ... Images Gum biopsy Tooth anatomy References Ellis E. Principles of differential diagnosis and biopsy. In: Hupp JR, ...

  20. Kidney Biopsy

    MedlinePlus

    ... the right diagnosis. What should a person do days before a kidney biopsy? Days before the procedure, ... procedure. What can a person expect on the day of the kidney biopsy? A person should arrive ...

  1. Immediate or early cord clamping vs delayed clamping.

    PubMed

    Hutchon, D J R

    2012-11-01

    Over the past 40 years, there have been a number of review articles attempting to rationalise cord clamping practice. Early cord clamping was originally thought to be important in active management of the third stage of labour, but this was never evidence based. Without an evidence base to justify it, early cord clamping in clinical practice has remained very variable. There is good evidence that early cord clamping leads to hypovolaemia, anaemia and low iron stores in the neonate. We review all the evidence and discuss possible reasons why some obstetricians and midwives persevere with early clamping. We explain how a variable definition, defective education, deferred responsibility between obstetrician and paediatrician, variable guidelines and a lack of appreciation for the potential harm of the intervention, have all contributed. This study describes how the need for early cord clamping can be avoided in practically all clinical complications of birth.

  2. Cantilever clamp fitting

    NASA Technical Reports Server (NTRS)

    Melton, Patrick B. (Inventor)

    1989-01-01

    A device is disclosed for sealing and clamping a cylindrical element which is to be attached to an object such as a wall, a pressurized vessel or another cylindrical element. The device includes a gland having an inner cylindrical wall, which is threaded at one end and is attached at a bendable end to a deformable portion, which in turn is attached to one end of a conical cantilever structure. The other end of the cantilever structure connects at a bendable area to one end of an outer cylindrical wall. The opposite end of cylindrical wall terminates in a thickened portion, the radially outer surface of which is adapted to accommodate a tool for rotating the gland. The terminal end of cylindrical wall also includes an abutment surface, which is adapted to engage a seal, which in turn engages a surface of a receiver. The receiver further includes a threaded portion for engagement with the threaded portion of gland whereby a tightening rotation of gland relative to receiver will cause relative movement between cylindrical walls and of gland. This movement causes a rotation of the conical structure and thus a bending action at bending area and at the bending end of the upper end of inner cylindrical wall. These rotational and bending actions result in a forcing of the deformable portion radially inwardly so as to contact and deform a pipe. This forcible contact creates a seal between gland and pipe, and simultaneously clamps the pipe in position.

  3. Inner Voltage Clamping

    PubMed Central

    Feldberg, Stephen W.; Delgado, Alicia B.

    1978-01-01

    Ketterer, et al. (1971) have suggested that a combination of electrostatic and chemical interactions may cause hydrophobic ions absorbed within a bilayer lipid membrane to reside in two potential wells, each close to a membrane surface. The resulting two planes of charges would define three regions of membrane dielectric: two identical outer regions each between a plane of absorbed charges and the plane of closest approach of ions in the aqueous phase; and the inner region between the two planes of adsorbed charges. The theory describing charge translocation across the inner region is based on a simple three-capacitor model. A significant theoretical conclusion is that the difference between the voltage across the inner region, Vi, and the voltage across the entire membrane, Vm, is directly proportional to the amount of charge that has flowed in a voltage clamp experiment. We demonstrate that we can construct an “inner voltage clamp” that can maintain, with positive feedback, a constant inner voltage, Vi. The manifestation of proper feedback is that the clamp current (after a voltage step) will exhibit pure (i.e., single time-constant) exponential decay, because the voltage dependent rate constants governing translocation will be independent of time. The “pureness” of the exponential is maximized when the standard deviation of the least-square fit of the appropriate exponential equation to the experimental data is minimized. The concomitant feedback is directly related to the capacitances of the inner and outer membrane regions, Ci and Co. Experimental results with tetraphenylborate ion adsorbed in bacterial phosphatidylethanolamine/n-decane bilayers indicate Ci ∼ 5 · 10-7F/cm2 and Co ≈ 5 · 10-5F/cm2. PMID:620078

  4. Cold knife cone biopsy

    MedlinePlus

    ... biopsy; Pap smear - cone biopsy; HPV - cone biopsy; Human papilloma virus - cone biopsy; Cervix - cone biopsy; Colposcopy - cone biopsy Images Female reproductive anatomy Cold cone biopsy Cold cone removal References American ...

  5. Getting the Most Out of Liver Biopsy.

    PubMed

    Lidbury, Jonathan A

    2017-05-01

    Histopathologic evaluation of liver biopsy specimens yields information that is not otherwise obtainable and is frequently essential for diagnosing hepatic disease. Percutaneous needle biopsy, laparoscopic biopsy, and surgical biopsy each have their own set of advantages and disadvantages. Care should be taken to ensure an adequate amount of tissue is collected for meaningful histologic evaluation. Because sampling error is a limitation of hepatic biopsy, multiple liver lobes should be biopsied. This article discusses the indications for liver biopsy, associated risks, advantages and disadvantages of different biopsy techniques, and strategies to get the most useful information possible out of this process. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Saddle Clamp With Captive Components

    NASA Technical Reports Server (NTRS)

    Belrose, Charles R.

    1993-01-01

    Saddle clamp modified to prevent parts from falling off when installed or removed. Allows easy access for tightening or loosening bolts, and retains alignment with tube mounted in it when opened. All parts are held captive - bolts by retaining washers, floating nuts by pressing and swaging, and upper clamp band by tether. Upper and lower bolt flanges offset from each other to ensure access.

  7. Liver Biopsy

    MedlinePlus

    ... for a liver biopsy by talking with a health care provider having blood tests arranging for a ride home fasting before the ... for a liver biopsy by talking with a health care provider having blood tests arranging for a ride home fasting before the ...

  8. Timing of cord clamping revisited.

    PubMed

    Levy, Tali; Blickstein, Isaac

    2006-01-01

    Although cord cutting has been performed since the beginning of mankind, the timing and advantages of early versus delayed cord clamping are still controversial. Early cord clamping (within the first 30 s after birth) is usually justified for potential prevention of postpartum hemorrhage and for immediate treatment of the newborn, but at the same time, may increase Rh-sensitization. Delayed cord clamping is performed after a period of 30 s during which 'placental transfusion' of approximately 80 mL of blood occurs. This amount seems to protect the baby from childhood anemia without increasing hypervolemia-related risks. In preterm infants, delayed clamping appears to reduce the risk of intraventricular hemorrhage and the need for neonatal transfusion. Obtaining cord blood for future autologous transplantation of stem cells needs early clamping and seems to conflict with the infant's best interest. Although a tailored approach is required in the case of cord clamping, the balance of available data suggests that delayed cord clamping should be the method of choice.

  9. Internal V-Band Clamp

    DOEpatents

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  10. Management of umbilical cord clamping.

    PubMed

    Webbon, Lucy

    2013-02-01

    The Royal College of Midwives (RCM) has updated its third stage of labour guidelines (RCM 2012) to be clearly supportive of a delay in umbilical cord clamping, although specific guidance on timing is yet to be announced. It is therefore imperative that both midwives and student midwives understand and are able to integrate delaying into their practice, as well as communicating to women the benefits; only in this way can we give women fully informed choices on this aspect of care. The main benefit of delayed cord clamping is the protection it can provide in reducing childhood anaemia, which is a major issue, especially in poorer countries. A review of the evidence found no risks linked to delayed clamping, and no evidence that it cannot be used in combination with the administration of uterotonic drugs. Delayed cord clamping can be especially beneficial for pre term and compromised babies.

  11. Synovial biopsy

    MedlinePlus

    ... abnormal buildup of iron deposits) Systemic lupus erythematosus (autoimmune disease that affects the skin, joints, and other organs) ... and the A.D.A.M. Editorial team. Autoimmune Diseases Read more Biopsy Read more Fungal Infections Read ...

  12. Bone Biopsy

    MedlinePlus

    ... than surgical biopsy and may not require general anesthesia. Tell your doctor about any recent illnesses or ... and whether you have any allergies, especially to anesthesia. Discuss any medications you’re taking, including herbal ...

  13. Tongue biopsy

    MedlinePlus

    ... Results Mean Abnormal results may mean: Amyloidosis Tongue (oral) cancer Viral ulcer Benign tumors Risks Risks for this ... D.A.M. Editorial team. Biopsy Read more Oral Cancer Read more Tongue Disorders Read more A.D. ...

  14. Ultrasound-guided synovial biopsy

    PubMed Central

    Sitt, Jacqueline C M; Wong, Priscilla

    2016-01-01

    Ultrasound-guided needle biopsy of synovium is an increasingly performed procedure with a high diagnostic yield. In this review, we discuss the normal synovium, as well as the indications, technique, tissue handling and clinical applications of ultrasound-guided synovial biopsy. PMID:26581578

  15. Overproduction and purification of RFC-related clamp loaders and PCNA-related clamps from Saccharomyces cerevisiae.

    PubMed

    Bylund, Göran O; Majka, Jerzy; Burgers, Peter M J

    2006-01-01

    The replication clamp PCNA and its loader RFC (Replication Factor C) are central factors required for processive replication and coordinated DNA repair. Recently, several additional related clamp loaders have been identified. These alternative clamp loaders contain the small Rfc2-5 subunits of RFC, but replace the large Rfc1 subunit by a pathway-specific alternative large subunit, Rad24 for the DNA damage checkpoint, Ctf18 for the establishment of sister chromatid cohesion, and Elg1 for a general function in chromosome stability. In order to define biochemical functions for these loaders, the loaders were overproduced in yeast and purified at a milligram scale. To aid in purification, the large subunit of each clamp loader was fused to a GST-tag that, after purification could be easily removed by a rhinoviral protease. This methodology yielded all clamp loaders in high yield and with high enzymatic activity. The yeast 9-1-1 checkpoint clamp, consisting of Rad17, Mec3, and Ddc1, was overproduced and purified in a similar manner.

  16. Patch Clamping Protoplasts from Vascular Plants 1

    PubMed Central

    Elzenga, J. Theo M.; Keller, Christopher P.; Van Volkenburgh, Elizabeth

    1991-01-01

    A method is described for the isolation of protoplasts (Pisum sativum, Phaseolus vulgaris, Avena sativa, Arabidopsis thaliana) in preparation for ion flux studies using patch clamp electrophysiology. Protoplasts that have been exposed to hydrolytic, cell wall degrading, enzymes for as little as 5 minutes form gigaseals (seal resistance higher than 10 giga Ohm) with the patch pipette with success rates greater than 40%. Sealing of these protoplasts is fast, averaging less than 2 minutes. This method yields high rates of gigaseal formation in a variety of tissues from both monocots and dicots and will enhance data collection in ion flux studies of plasma membranes of vascular plants. PMID:16668586

  17. Split-tapered joint clamping device

    DOEpatents

    Olsen, Max J.; Schwartz, Jr., John F.

    1988-01-01

    This invention relates to a clamping device for removably attaching a tool element to a bracket element wherein a bracket element is disposed in a groove in the tool and a clamping member is disposed in said groove and in engagement with a clamping face of the bracket and a wall of the groove and with the clamping member having pivot means engaging the bracket and about which the clamping member rotates.

  18. Micromachined patch-clamp apparatus

    SciTech Connect

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  19. Skin Biopsy

    MedlinePlus

    ... a biopsy because of a tumor, lump, or mass, don't hit the panic button. Often, a lump or bump is benign, which means it's not cancerous. If you're worried, talk with your doctor, your ... For Teens For Kids ...

  20. Limit analysis of pipe clamps

    SciTech Connect

    Flanders, H.E. Jr.

    1990-01-01

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer's rated loads. 3 refs.

  1. Laparoscopic Biopsies in Pancreas Transplantation.

    PubMed

    Uva, P D; Odorico, J S; Giunippero, A; Cabrera, I C; Gallo, A; Leon, L R; Minue, E; Toniolo, F; Gonzalez, I; Chuluyan, E; Casadei, D H

    2017-08-01

    As there is no precise laboratory test or imaging study for detection of pancreas allograft rejection, there is increasing interest in obtaining pancreas tissue for diagnosis. Pancreas allograft biopsies are most commonly performed percutaneously, transcystoscopically, or endoscopically, yet pancreas transplant surgeons often lack the skills to perform these types of biopsies. We have performed 160 laparoscopic pancreas biopsies in 95 patients. There were 146 simultaneous kidney-pancreas biopsies and 14 pancreas-only biopsies due to pancreas alone, kidney loss, or extraperitoneal kidney. Biopsies were performed for graft dysfunction (89) or per protocol (71). In 13 cases, an additional laparoscopic procedure was performed at the same operation. The pancreas diagnostic tissue yield was 91.2%; however, the pancreas could not be visualized in eight cases (5%) and in 6 cases the tissue sample was nondiagnostic (3.8%). The kidney tissue yield was 98.6%. There were four patients with intraoperative complications requiring laparotomy (2.5%) with two additional postoperative complications. Half of all these complications were kidney related. There were no episodes of pancreatic enzyme leak and there were no graft losses related to the procedure. We conclude that laparoscopic kidney and pancreas allograft biopsies can be safely performed with very high tissue yields. © 2017 The American Society of Transplantation and the American Society of Transplant Surgeons.

  2. Whole-GUV patch-clamping.

    PubMed

    Garten, Matthias; Mosgaard, Lars D; Bornschlögl, Thomas; Dieudonné, Stéphane; Bassereau, Patricia; Toombes, Gilman E S

    2017-01-10

    Studying how the membrane modulates ion channel and transporter activity is challenging because cells actively regulate membrane properties, whereas existing in vitro systems have limitations, such as residual solvent and unphysiologically high membrane tension. Cell-sized giant unilamellar vesicles (GUVs) would be ideal for in vitro electrophysiology, but efforts to measure the membrane current of intact GUVs have been unsuccessful. In this work, two challenges for obtaining the "whole-GUV" patch-clamp configuration were identified and resolved. First, unless the patch pipette and GUV pressures are precisely matched in the GUV-attached configuration, breaking the patch membrane also ruptures the GUV. Second, GUVs shrink irreversibly because the membrane/glass adhesion creating the high-resistance seal (>1 GΩ) continuously pulls membrane into the pipette. In contrast, for cell-derived giant plasma membrane vesicles (GPMVs), breaking the patch membrane allows the GPMV contents to passivate the pipette surface, thereby dynamically blocking membrane spreading in the whole-GMPV mode. To mimic this dynamic passivation mechanism, beta-casein was encapsulated into GUVs, yielding a stable, high-resistance, whole-GUV configuration for a range of membrane compositions. Specific membrane capacitance measurements confirmed that the membranes were truly solvent-free and that membrane tension could be controlled over a physiological range. Finally, the potential for ion transport studies was tested using the model ion channel, gramicidin, and voltage-clamp fluorometry measurements were performed with a voltage-dependent fluorophore/quencher pair. Whole-GUV patch-clamping allows ion transport and other voltage-dependent processes to be studied while controlling membrane composition, tension, and shape.

  3. Electrically integrated SU-8 clamped graphene drum resonators for strain engineering

    NASA Astrophysics Data System (ADS)

    Lee, Sunwoo; Chen, Changyao; Deshpande, Vikram V.; Lee, Gwan-Hyoung; Lee, Ilkyu; Lekas, Michael; Gondarenko, Alexander; Yu, Young-Jun; Shepard, Kenneth; Kim, Philip; Hone, James

    2013-04-01

    Graphene mechanical resonators are the ultimate two-dimensional nanoelectromechanical systems (NEMS) with applications in sensing and signal processing. While initial devices have shown promising results, an ideal graphene NEMS resonator should be strain engineered, clamped at the edge without trapping gas underneath, and electrically integratable. In this Letter, we demonstrate fabrication and direct electrical measurement of circular SU-8 polymer-clamped chemical vapor deposition graphene drum resonators. The clamping increases device yield and responsivity, while providing a cleaner resonance spectrum from eliminated edge modes. Furthermore, the clamping induces a large strain in the resonator, increasing its resonant frequency.

  4. Is early cord clamping, delayed cord clamping or cord milking best?

    PubMed

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2017-03-20

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p < .05) lower in the early cord clamping group compared with the other two groups. The disulfide/total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  5. Delayed umbilical cord clamping in premature neonates.

    PubMed

    Kaempf, Joseph W; Tomlinson, Mark W; Kaempf, Andrew J; Wu, YingXing; Wang, Lian; Tipping, Nicole; Grunkemeier, Gary

    2012-08-01

    Delayed umbilical cord clamping is reported to increase neonatal blood volume. We estimated the clinical outcomes in premature neonates who had delayed umbilical cord clamping compared with a similar group who had early umbilical cord clamping. This was a before-after investigation comparing early umbilical cord clamping with delayed umbilical cord clamping (45 seconds) in two groups of singleton neonates, very low birth weight (VLBW) (401-1,500 g) and low birth weight (LBW) (greater than 1,500 g but less than 35 weeks gestation). Neonates were excluded from delayed umbilical cord clamping if they needed immediate major resuscitation. Primary outcomes were provision of delivery room resuscitation, hematocrit, red cell transfusions, and the principle Vermont Oxford Network outcomes. In VLBW neonates (77 delayed umbilical cord clamping, birth weight [mean±standard deviation] 1,099±266 g; 77 early umbilical cord clamping 1,058±289 g), delayed umbilical cord clamping was associated with less delivery room resuscitation, higher Apgar scores at 1 minute, and higher hematocrit. Delayed umbilical cord clamping was not associated with significant differences in the overall transfusion rate, peak bilirubin, any of the principle Vermont Oxford Network outcomes, or mortality. In LBW neonates (172 delayed umbilical cord clamping, birth weight [mean±standard deviation] 2,159±384 g; 172 early umbilical cord clamping 2,203±447 g), delayed umbilical cord clamping was associated with higher hematocrit and was not associated with a change in delivery room resuscitation or Apgar scores or with changes in the transfusion rate or peak bilirubin. Regression analysis showed increasing gestational age and birth weight and delayed umbilical cord clamping were the best predictors of higher hematocrit and less delivery room resuscitation. Delayed umbilical cord clamping can safely be performed in singleton premature neonates and is associated with a higher hematocrit, less delivery room

  6. The RFC clamp loader: structure and function.

    PubMed

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  7. Cardiac and renal responses to cross-clamping of the descending thoracic aorta.

    PubMed

    Roberts, A J; Nora, J D; Hughes, W A; Quintanilla, A P; Ganote, C E; Sanders, J H; Moran, J M; Michaelis, L L

    1983-11-01

    The present study was performed to document the relative efficacy of commonly applied techniques used adjunctively during 1 hour of descending thoracic aortic cross-clamping. Renal and cardiac responses were determined by standard laboratory methods. There were four experimental groups: (1) heparin-bonded shunt; (2) partial femoral-femoral bypass; (3) sodium nitroprusside; (4) control. Each of the experimental groups showed abnormal hemodynamic responses during cross-clamping. Elevations in left ventricular end-diastolic pressure (LVEDP) and systolic blood pressure were common events during clamping, and cardiac output often decreased. Nevertheless, left ventricular performance curves after cross-clamping showed similar increases in left ventricular stroke work (LVSW) with increasing preload. In addition, left ventricular biopsy specimens showed preservation of myocardial high-energy phosphate stores and essentially normal ultrastructural integrity. Radioactive microspheres generally showed increased myocardial blood flow during and after cross-clamping, but no evidence of preferential subendocardial ischemia. Examination of renal function showed a marked decrease in urine output, glomerular filtration rate, and renal plasma flow during cross-clamping. Following the release of the cross-clamp, renal function returned to 50% to 85% of baseline status. Since we could find no major advantage of any of the techniques employed under the present experimental conditions, we suggest that all of the techniques should be part of the surgical armamentarium and the particular preoperative and/or intraoperative findings in a specific case should determine which technique is most appropriate for a given patient.

  8. From overshoot to voltage clamp.

    PubMed

    Huxley, Andrew

    2002-11-01

    In 1939, A.L. Hodgkin and I found that the nerve action potential shows an "overshoot"--that is, the interior of the fibre becomes electrically positive during an action potential. In 1948, we did our first experiments with a voltage clamp to investigate the current-voltage relations of the nerve membrane. Between those dates, we spent much time speculating about the mechanism by which ions cross the membrane and how the action potential is generated. This article summarizes these speculations, none of which has been previously published.

  9. High-speed pressure clamp.

    PubMed

    Besch, Stephen R; Suchyna, Thomas; Sachs, Frederick

    2002-10-01

    We built a high-speed, pneumatic pressure clamp to stimulate patch-clamped membranes mechanically. The key control element is a newly designed differential valve that uses a single, nickel-plated piezoelectric bending element to control both pressure and vacuum. To minimize response time, the valve body was designed with minimum dead volume. The result is improved response time and stability with a threefold decrease in actuation latency. Tight valve clearances minimize the steady-state air flow, permitting us to use small resonant-piston pumps to supply pressure and vacuum. To protect the valve from water contamination in the event of a broken pipette, an optical sensor detects water entering the valve and increases pressure rapidly to clear the system. The open-loop time constant for pressure is 2.5 ms for a 100-mmHg step, and the closed-loop settling time is 500-600 micros. Valve actuation latency is 120 micros. The system performance is illustrated for mechanically induced changes in patch capacitance.

  10. [A clamp for suturing of duodenal stump].

    PubMed

    Komarov, I A

    1991-03-01

    An original clamp was used in suturing a duodenal stump after gastric resection in 77 patients. The complex relief of the blades of the clamp holds the duodenum reliably during application of the sutures and ensures their air-tightness. The trauma inflicted to the duodenum in this case is minimal. During resection of the stomach in 37 patients the author used the clamp in closure of the lesser curvature. Incompetence of the duodenal stump was not encountered.

  11. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, Bruce P.; Sleefe, Gerard E.; Striker, Richard P.

    1993-01-01

    A borehole seismic tool including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric meter in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  12. Advanced motor driven clamped borehole seismic receiver

    DOEpatents

    Engler, B.P.; Sleefe, G.E.; Striker, R.P.

    1993-02-23

    A borehole seismic tool is described including a borehole clamp which only moves perpendicular to the borehole. The clamp is driven by an electric motor, via a right angle drive. When used as a seismic receiver, the tool has a three part housing, two of which are hermetically sealed. Accelerometers or geophones are mounted in one hermetically sealed part, the electric motor in the other hermetically sealed part, and the clamp and right angle drive in the third part. Preferably the tool includes cable connectors at both ends. Optionally a shear plate can be added to the clamp to extend the range of the tool.

  13. Bone biopsy (image)

    MedlinePlus

    A bone biopsy is performed by making a small incision into the skin. A biopsy needle retrieves a sample of bone and it ... examination. The most common reasons for bone lesion biopsy are to distinguish between benign and malignant bone ...

  14. Muscle biopsy (image)

    MedlinePlus

    A muscle biopsy involves removal of a plug of tissue usually by a needle to be later used for examination. Sometimes ... there is a patchy condition expected an open biopsy may be used. Open biopsy involves a small ...

  15. Pleural needle biopsy

    MedlinePlus

    ... of the pleural membrane. Pleural biopsy can diagnose tuberculosis , cancer, and other diseases. If this type of pleural biopsy is not enough to make a diagnosis, you may need a surgical biopsy of the ...

  16. Navigation-guided endoscopic biopsy for intraparenchymal brain tumor.

    PubMed

    Tsuda, Kyoji; Ishikawa, Eiichi; Zaboronok, Alexander; Nakai, Kei; Yamamoto, Tetsuya; Sakamoto, Noriaki; Uemae, Yoji; Tsurubuchi, Takao; Akutsu, Hiroyoshi; Ihara, Satoshi; Ayuzawa, Satoshi; Takano, Shingo; Matsumura, Akira

    2011-01-01

    To evaluate the efficacy of intraparenchymal brain tumor biopsy using endoscopy and a navigation system (navigation-guided endoscopic biopsy) as a diagnostic tool, a case series of intraparenchymal tumor biopsies was reviewed. Navigation-guided endoscopic biopsy was applied in 9 cases, stereotactic needle biopsy in 16 cases, and open biopsy with or without navigation system in 34 cases. In all biopsy cases, 84.7% of biopsy points were sampled accurately, and 93.2% of diagnoses by biopsy were correct. Comparison of each type of biopsy showed that the resected volumes in navigation-guided endoscopic biopsy and open biopsy tended to be larger than those in stereotactic biopsy, and the mean operation time for the open biopsy procedure was the longest. To define the most applicable device or examination method to increase sampling accuracy, various factors were analyzed in 59 procedures. Navigation-guided endoscopic biopsy was the most accurate of the three types of biopsy, although the statistical difference was not significant. Older patients, histological diagnosis of high-grade glioma or malignant lymphoma, positive photodynamic diagnosis, and positive intraoperative pathology were significant factors in improving the sampling accuracy. Navigation-guided endoscopic biopsy could provide a larger sample volume within a relatively short operation time. The biopsy can be easily combined with both photodynamic diagnosis and intraoperative pathology, significantly improving the histological diagnostic yield.

  17. 21 CFR 870.4450 - Vascular clamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular...

  18. Time to implement delayed cord clamping.

    PubMed

    McAdams, Ryan M

    2014-03-01

    Immediate umbilical cord clamping after delivery is routine in the United States despite little evidence to support this practice. Numerous trials in both term and preterm neonates have demonstrated the safety and benefit of delayed cord clamping. In premature neonates, delayed cord clamping has been shown to stabilize transitional circulation, lessening needs for inotropic medications and reducing blood transfusions, necrotizing enterocolitis, and intraventricular hemorrhage. In term neonates, delayed cord clamping has been associated with decreased iron-deficient anemia and increased iron stores with potential valuable effects that extend beyond the newborn period, including improvements in long-term neurodevelopment. The failure to more broadly implement delayed cord clamping in neonates ignores published benefits of increased placental blood transfusion at birth and may represent an unnecessary harm for vulnerable neonates.

  19. Combat ready clamp medic technique.

    PubMed

    Tovmassian, Robert V; Kragh, John F; Dubick, Michael A; Baer, David G; Blackbourne, Lorne H

    2012-01-01

    Junctional hemorrhage control device use on the battlefield might be lifesaving, but little experience is reported. The purpose of the present case report is to detail prehospital use of the Combat Ready Clamp (called the CRoC by its users, Combat Medical Systems, Fayetteville, NC; Instructions for Use, 2010) in casualty care in order to increase awareness of junctional hemorrhage control. The CRoC was used to control difficult inguinal bleeding on the battlefield for an Afghani man with a hindquarter traumatic amputation. The device promptly controlled exsanguination from a critical injury when placed during rotary-wing casualty evacuation. The flight medic applied the device in 90 seconds. The device performed well without complications to control bleeding. The CRoC, a new junctional hemorrhage control device, was used as indicated on the battlefield with mechanical and physiologic success and without device problems. By controlling difficult inguinal bleeding resulting from battlefield trauma, the device facilitated casualty stabilization and delivery to a surgical facility. The device facilitated the ability of a new flight medic to focus his expertise on a critically injured battlefield casualty with demonstrable success. 2012.

  20. The monogenean which lost its clamps.

    PubMed

    Justine, Jean-Lou; Rahmouni, Chahrazed; Gey, Delphine; Schoelinck, Charlotte; Hoberg, Eric P

    2013-01-01

    Ectoparasites face a daily challenge: to remain attached to their hosts. Polyopisthocotylean monogeneans usually attach to the surface of fish gills using highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 60 years ago, the clamps were considered to be absent but few specimens were available and this observation was later questioned. In addition, genera within the family Protomicrocotylidae have either clamps of the "gastrocotylid" or the "microcotylid" types; this puzzled systematists because these clamp types are characteristic of distinct, major groups. Discovery of another, new, species of the genus Lethacotyle, has allowed us to explore the nature of the attachment structures in protomicrocotylids. Lethacotyle vera n. sp. is described from the gills of the carangid Caranx papuensis off New Caledonia. It is distinguished from Lethacotyle fijiensis, the only other species of the genus, by the length of the male copulatory spines. Sequences of 28S rDNA were used to build a tree, in which Lethacotyle vera grouped with other protomicrocotylids. The identity of the host fish was confirmed with COI barcodes. We observed that protomicrocotylids have specialized structures associated with their attachment organ, such as lateral flaps and transverse striations, which are not known in other monogeneans. We thus hypothesized that the clamps in protomicrocotylids were sequentially lost during evolution, coinciding with the development of other attachment structures. To test the hypothesis, we calculated the surfaces of clamps and body in 120 species of gastrocotylinean monogeneans, based on published descriptions. The ratio of clamp surface: body surface was the lowest in protomicrocotylids. We conclude that clamps in protomicrocotylids are vestigial organs, and that occurrence of "gastrocotylid" and simpler "microcotylid" clamps within the same family are steps in an

  1. The Monogenean Which Lost Its Clamps

    PubMed Central

    Justine, Jean-Lou; Rahmouni, Chahrazed; Gey, Delphine; Schoelinck, Charlotte; Hoberg, Eric P.

    2013-01-01

    Ectoparasites face a daily challenge: to remain attached to their hosts. Polyopisthocotylean monogeneans usually attach to the surface of fish gills using highly specialized structures, the sclerotized clamps. In the original description of the protomicrocotylid species Lethacotyle fijiensis, described 60 years ago, the clamps were considered to be absent but few specimens were available and this observation was later questioned. In addition, genera within the family Protomicrocotylidae have either clamps of the “gastrocotylid” or the “microcotylid” types; this puzzled systematists because these clamp types are characteristic of distinct, major groups. Discovery of another, new, species of the genus Lethacotyle, has allowed us to explore the nature of the attachment structures in protomicrocotylids. Lethacotyle vera n. sp. is described from the gills of the carangid Caranx papuensis off New Caledonia. It is distinguished from Lethacotyle fijiensis, the only other species of the genus, by the length of the male copulatory spines. Sequences of 28S rDNA were used to build a tree, in which Lethacotyle vera grouped with other protomicrocotylids. The identity of the host fish was confirmed with COI barcodes. We observed that protomicrocotylids have specialized structures associated with their attachment organ, such as lateral flaps and transverse striations, which are not known in other monogeneans. We thus hypothesized that the clamps in protomicrocotylids were sequentially lost during evolution, coinciding with the development of other attachment structures. To test the hypothesis, we calculated the surfaces of clamps and body in 120 species of gastrocotylinean monogeneans, based on published descriptions. The ratio of clamp surface: body surface was the lowest in protomicrocotylids. We conclude that clamps in protomicrocotylids are vestigial organs, and that occurrence of “gastrocotylid” and simpler “microcotylid” clamps within the same family are

  2. Surface characterization of selected LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromer, T. F.; Grammer, H. L.; Wightman, J. P.; Young, Philip R.; Slemp, Wayne S.

    1993-01-01

    The surface characterization of chromic acid anodized 6061-T6 aluminum alloy tray clamps has shown differences in surface chemistry depending upon the position on the Long Duration Exposure Facility (LDEF). Water contact angle results showed no changes in wettability of the tray clamps. The overall surface topography of the control, trailing edge(E3) and leading edge(D9) samples was similar. The thickness of the aluminum oxide layer for all samples determined by Auger depth profiling was less than one micron. X-ray photoelectron spectroscopy (XPS) analysis of the tray clamps showed significant differences in the surface composition. Carbon and silicon containing compounds were the primary contaminants detected.

  3. Dynamic clamp with StdpC software.

    PubMed

    Kemenes, Ildikó; Marra, Vincenzo; Crossley, Michael; Samu, Dávid; Staras, Kevin; Kemenes, György; Nowotny, Thomas

    2011-03-01

    Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, for spike timing-dependent plasticity clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real-time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments through an intuitive and powerful interface with a minimal initial lead time of a few hours. After initial configuration, experimental results can be generated within minutes of establishing cell recording.

  4. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    NASA Astrophysics Data System (ADS)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  5. Clamp force and alignment checking device

    DOEpatents

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  6. Improved Algorithm for Automated Glucose Clamps.

    PubMed

    Kuhlenkötter, Mareike; Heise, Tim; Benesch, Carsten

    2017-02-01

    In glucose clamp experiments, blood glucose concentrations (BGs) are kept as close as possible to a predefined target level using variable glucose infusion rates (GIRs). In automated clamps, GIRs are calculated by algorithms implemented in the device (e.g., the Biostator). Low BG- and GIR-variability is needed for high clamp quality. We therefore tried to reduce oscillations in both BG and GIR with an improved algorithm implemented in ClampArt, a modern clamp device. The Biostator algorithm was first improved by numerical simulations of glucose clamps (in silico). With the results of the simulations, we started in vitro experiments using the ClampArt device and a container with water and glucose as "test subject." After a small pilot in vivo study, a larger clinical study was performed to compare the original with the optimized algorithm. With the improved algorithm, in silico, in vitro, and in vivo experiments showed reduced oscillations in both BG and GIR. In the clinical study, the coefficient of variation (CV) of BG values was lowered from 6.0% (4.6%-7.8%) [median (interquartile range)] to 4.2% (3.6%-5.0%), P < 0.0001 and the CV of GIR from 60.7% (49.6%-82.0%) to 43.5% (32.8%-57.2%), P < 0.0001. Other clamp quality parameters did not change substantially, median deviation from target slightly increased from 0.6% (0.2%-1.0%) to 1.1% (0.7%-1.5%), P = 0.0005, whereas utility did not change [97.0% (93.4%-100.0%) vs. 97.0% (94.0%-98.8%), P = 0.57]. With the improved algorithm, all experiments confirmed a reduction in BG- and GIR-oscillations without a major impact on other glucose clamp parameters. The optimized algorithm has been implemented in ClampArt for all future glucose clamp studies.

  7. Structural analysis of a eukaryotic sliding DNA clamp-clamp loadercomplex.

    SciTech Connect

    Bowman, Gregory D.; O'Donnell, Mike; Kuriyan, John

    2006-06-17

    Sliding clamps are ring-shaped proteins that encircle DNA and confer high processivity on DNA polymerases. Here we report the crystal structure of the five-protein clamp loader complex (replication factor-C, RFC) of the yeast Saccharomyces cerevisiae, bound to the sliding clamp (proliferating cell nuclear antigen, PCNA). Tight interfacial coordination of the ATP analogue ATP-?-S by RFC results in a spiral arrangement of the ATPase domains of the clamp loader above the PCNA ring. Placement of a model for primed DNA within the central hole of PCNA reveals a striking correspondence between the RFC spiral and the grooves of the DNA double helix. This model, in which the clamp loader complex locks onto primed DNA in a screw-cap-like arrangement, provides a simple explanation for the process by which the engagement of primer-template junctions by the RFC:PCNA complex results in ATP hydrolysis and release of the sliding clamp on DNA.

  8. Diverless pipeline repair clamp: Phase 1

    SciTech Connect

    Miller, J.E.; Knott, B. )

    1991-12-01

    Offshore oil and gas developments are underway for water depths beyond which divers can function. The economic lifelines of these projects are the pipelines which will transport the products to shore. In preparation for the day when one of these pipelines will require repair because of a leak, the Pipeline Research Committee of the American Gas Association is funding research directed at developing diverless pipeline repair capabilities. Several types of damage are possible, ranging from latent weld defects on one end of the spectrum to damage resulting in parting of the pipe at the other end. This study is specifically directed toward laying the groundwork for development of a diverless pipeline repair clamp for use in repair of leaks resulting from minor pipe defects. The incentive for a clamp type repair is costs. When compared to replacing a section of pipe, either by welding or by mechanical means, the clamp type repair requires much less disturbance of the pipe, less time, fewer operations and less equipment. This report summarizes (1) capabilities of remotely operated vehicles (ROV's) and associated systems, (2) highlights areas for further research and development, (3) describes the required capabilities of the diverless repairclamp, (4) investigates some alternatives to the diverless clamp, (5) overviews the state of the art in leak repair clamps, and (6) critiques several possible generic clamp concepts.

  9. Sound absorption by clamped poroelastic plates.

    PubMed

    Aygun, H; Attenborough, K

    2008-09-01

    Measurements and predictions have been made of the absorption coefficient and the surface acoustic impedance of poroelastic plates clamped in a large impedance tube and separated from the rigid termination by an air gap. The measured and predicted absorption coefficient and surface impedance spectra exhibit low frequency peaks. The peak frequencies observed in the absorption coefficient are close to those predicted and measured in the deflection spectra of the clamped poroelastic plates. The influences of the rigidity of the clamping conditions and the width of the air gap have been investigated. Both influences are found to be important. Increasing the rigidity of clamping reduces the low frequency absorption peaks compared with those measured for simply supported plates or plates in an intermediate clamping condition. Results for a closed cell foam plate and for two open cell foam plates made from recycled materials are presented. For identical clamping conditions and width of air gap, the results for the different materials differ as a consequence mainly of their different elasticity, thickness, and cell structure.

  10. Optimization of prostate biopsy

    NASA Astrophysics Data System (ADS)

    Bauer, John J.; Zeng, Jianchao; Weir, James; Zhang, Wei; Sesterhenn, Isabell A.; Connelly, Roger R.; Moul, Judd W.; Mun, Seong K.

    1999-05-01

    Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error. We have developed a novel 3D computer assisted prostate biopsy simulator based upon 201 whole- mounted step-sectioned radical prostatectomy specimens to compare the diagnostic accuracy of various prostate needle biopsy protocols. Computerized prostate models have been developed to accurately depict the anatomy of the prostate and all individual tumor foci. We obtained 18-biopsies of each prostate model to determine the detection rates of various biopsy protocols. As a result, the 10- and 12- pattern biopsy protocols had a 99.0 percent detection rate, while the traditional sextant biopsy protocol rate was only 72.6 percent. The 5-region biopsy protocol had a 90.5 percent detection rate. the lateral sextant pattern revealed a detection rate of 95.5 percent, whereas the 4-pattern lateral biopsy protocol had a 93.5 percent detection rate. Our results suggest that all the biopsy protocols that use laterally placed biopsies based upon the five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Lateral biopsies in the mid and apical zones of the gland are the most important.

  11. Tenderization of hot-boned broiler breast meat by clamping during chilling.

    PubMed

    Cason, J A; Lyon, C E; Dickens, J A

    2002-01-01

    Hot-boned broiler breast fillets were tightly clamped between rigid aluminum plates during chilling to determine whether tenderness is increased if breast fillets are not allowed to shorten during rigor. In two experiments, 6-wk-old broilers were processed in a pilot plant. Approximately 5 min after evisceration, the breast fillets (pectoralis major) were deboned, and each fillet was subjected to one of two treatments while chilling for 2 h in ice slush. Fillets were placed in perforated plastic bags (hot-boned control) or clamped between rigid aluminum plates that compressed the meat to a uniform thickness of 7.2 mm during chilling. In Experiment 2, chilling time in ice slush was 1 h, and a third treatment was added to make an incomplete block design in which one breast half was left intact on the carcass and was deboned immediately after chilling. All breast fillets were sealed in plastic bags after the chilling period, held overnight at 4 C, and then cooked at 85 C for 30 min in a steam kettle. In Experiment 1, clamping for 2 h reduced Warner-Bratzler shear values of hot-boned fillets from 11.4 to 2.7 kg. In Experiment 2, shear values for the treatments were 13.0, 9.2, and 5.1 kg for the hot-boned, cold-boned, and hot-boned clamped treatments, respectively, with significantly lower shear values for the clamped fillets. Clamped fillets were significantly thinner than the control fillets in both experiments. Cooked yield as a percentage of postchill weight was significantly higher for the clamped compared to the hot-boned control pieces, 81.1 versus 77.3%, with cold-boned pieces being intermediate and not different from the other treatments. Shear values were reduced, and cooked yield was increased by clamping hot-boned fillets during chilling.

  12. Sentinel node biopsy (image)

    MedlinePlus

    Sentinel node biopsy is a technique which helps determine if a cancer has spread (metastasized), or is contained locally. When a ... is closest to the cancer site. Sentinel node biopsy is used to stage many kinds of cancer, ...

  13. Nerve biopsy (image)

    MedlinePlus

    Nerve biopsy is the removal of a small piece of nerve for examination. Through a small incision, a sample ... is removed and examined under a microscope. Nerve biopsy may be performed to identify nerve degeneration, identify ...

  14. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  15. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  16. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Cable clamps and grips. 18.40 Section 18.40... Requirements § 18.40 Cable clamps and grips. Insulated clamps shall be provided for all portable (trailing) cables to prevent strain on the cable terminals of a machine. Also insulated clamps shall be provided to...

  17. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  18. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  19. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  20. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  1. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures....

  2. Piezoresistive cantilever force-clamp system

    SciTech Connect

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L.; Goodman, Miriam B.

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  3. An Ultrasonic Clamp for Bloodless Partial Nephrectomy

    NASA Astrophysics Data System (ADS)

    Lafon, Cyril; Bouchoux, Guillaume; Murat, François Joseph; Birer, Alain; Theillère, Yves; Chapelon, Jean Yves; Cathignol, Dominique

    2007-05-01

    Maximum conservation of the kidney is preferable through partial nephrectomy for patients at risk of disease recurrence of renal cancers. Haemostatic tools are needed in order to achieve bloodless surgery and reduce post surgery morbidity. Two piezo-ceramic transducers operating at a frequency of 4 MHz were mounted on each arm of a clamp. When used for coagulation purposes, two transducers situated on opposite arms of the clamp were driven simultaneously. Heat delivery was optimized as each transducers mirrored back to targeted tissues the wave generated by the opposite transducer. Real-time treatment monitoring with an echo-based technique was also envisaged with this clamp. Therapy was periodically interrupted so one transducer could generate a pulse. The echo returning from the opposite transducer was treated. Coagulation necroses were obtained in vitro on substantial thicknesses (23-38mm) of pig liver over exposure durations ranging from 30s to 130s, and with acoustic intensities of less than 15W/cm2 per transducer. Both kidneys of two pigs were treated in vivo with the clamp (14.5W/cm2 for 90s), and the partial nephrectomies performed proved to be bloodless. In vitro and in vivo, wide transfixing lesions corresponded to an echo energy decrease superior to -10dB and parabolic form of the time of flight versus treatment time. In conclusion, this ultrasound clamp has proven to be an excellent mean for achieving monitored haemostasis in kidney.

  4. Abdominal wall fat pad biopsy

    MedlinePlus

    Amyloidosis - abdominal wall fat pad biopsy; Abdominal wall biopsy; Biopsy - abdominal wall fat pad ... method of taking an abdominal wall fat pad biopsy . The health care provider cleans the skin on ...

  5. Compact, Stiff, Remotely-Actuable Quick-Release Clamp

    NASA Technical Reports Server (NTRS)

    Tsai, Ted W. (Inventor)

    2000-01-01

    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  6. The pathophysiology of aortic cross-clamping.

    PubMed

    Zammert, Martin; Gelman, Simon

    2016-09-01

    During open aortic surgery, interrupting the blood flow through the aorta by applying a cross-clamp is often a key step to allow for surgical repair. As a consequence, ischemia is induced in parts of the body distal to the clamp site. This significant alteration in the blood flow is almost always associated with hemodynamic changes. Upon release of the cross-clamp, the blood flow is restored, triggering an ischemia-reperfusion response, leading to many pathophysiological processes such as inflammation, humoral changes, and metabolite circulation that could lead to injury in many organ systems and may significantly influence the postoperative outcome. It is therefore important to understand these processes and how they can be treated in order to allow for safe surgical aortic repairs while ensuring the best possible outcomes.

  7. Multiple Biopsies and Detection of Cervical Cancer Precursors at Colposcopy

    PubMed Central

    Wentzensen, Nicolas; Walker, Joan L.; Gold, Michael A.; Smith, Katie M.; Zuna, Rosemary E.; Mathews, Cara; Dunn, S. Terence; Zhang, Roy; Moxley, Katherine; Bishop, Erin; Tenney, Meaghan; Nugent, Elizabeth; Graubard, Barry I.; Wacholder, Sholom; Schiffman, Mark

    2015-01-01

    Purpose Women with abnormal cervical cancer screening results are referred to colposcopy and biopsy for diagnosis of cervical cancer precursors (high-grade squamous intraepithelial lesions [HSILs]). Colposcopy with a single biopsy can miss identification of HSILs. No systematic study has quantified the improved detection of HSIL by taking multiple lesion-directed biopsies. Methods The Biopsy Study was an observational study of 690 women referred to colposcopy after abnormal cervical cancer screening results. Up to four directed biopsies were taken from distinct acetowhite lesions and ranked by colposcopic impression. A nondirected biopsy of a normal-appearing area was added if fewer than four directed biopsies were taken. HSIL identified by any biopsy was the reference standard of disease used to evaluate the incremental yield and sensitivity of multiple biopsies. Results In the overall population, sensitivities for detecting HSIL increased from 60.6% (95% CI, 54.8% to 66.6%) from a single biopsy to 85.6% (95% CI, 80.3% to 90.2%) after two biopsies and to 95.6% (95% CI, 91.3% to 99.2%) after three biopsies. A significant increase in sensitivity of multiple biopsies was observed in all subgroups. The highest increase in yield of HSIL was observed for women with a high-grade colposcopic impression, HSIL cytology, and human papillomavirus (HPV) type 16 positivity. Only 2% of all HSILs diagnosed in the participants were detected by biopsies of normal-appearing transformation zone. Conclusion Collection of additional lesion-directed biopsies during colposcopy increased detection of histologic HSIL, regardless of patient characteristics. Taking additional biopsies when multiple lesions are present should become the standard practice of colposcopic biopsy. PMID:25422481

  8. Geometric systematic prostate biopsy.

    PubMed

    Chang, Doyoung; Chong, Xue; Kim, Chunwoo; Jun, Changhan; Petrisor, Doru; Han, Misop; Stoianovici, Dan

    2017-04-01

    The common sextant prostate biopsy schema lacks a three-dimensional (3D) geometric definition. The study objective was to determine the influence of the geometric distribution of the cores on the detection probability of prostate cancer (PCa). The detection probability of significant (>0.5 cm(3)) and insignificant (<0.2 cm(3)) tumors was quantified based on a novel 3D capsule model of the biopsy sample. The geometric distribution of the cores was optimized to maximize the probability of detecting significant cancer for various prostate sizes (20-100cm(3)), number of biopsy cores (6-40 cores) and biopsy core lengths (14-40 mm) for transrectal and transperineal biopsies. The detection of significant cancer can be improved by geometric optimization. With the current sextant biopsy, up to 20% of tumors may be missed at biopsy in a 20 cm(3) prostate due to the schema. Higher number and longer biopsy cores are required to sample with an equal detection probability in larger prostates. Higher number of cores increases both significant and insignificant tumor detection probability, but predominantly increases the detection of insignificant tumors. The study demonstrates mathematically that the geometric biopsy schema plays an important clinical role, and that increasing the number of biopsy cores is not necessarily helpful.

  9. Perspectives on implementing delayed cord clamping.

    PubMed

    Leslie, Mayri Sagady

    2015-01-01

    Expanding evidence supports delayed cord clamping (DCC) for both term and preterm infants. This article explores issues that may be keeping early cord clamping (ECC) in place as usual practice. Professional organizations almost universally recommend DCC for preterm infants, but some reserve recommending it for term infants only in resource-poor settings. Concerns about polycythemia and jaundice persist in the literature, while years of published randomized controlled trials do not support the assumptions behind the concerns. New data suggest that DCC may improve resuscitative efforts in compromised infants. Multiple perspectives are offered for consideration when thinking about incorporating DCC into practice. © 2015 AWHONN.

  10. Complications of prostate biopsy.

    PubMed

    Anastasiadis, Anastasios; Zapała, Lukasz; Cordeiro, Ernesto; Antoniewicz, Artur; Dimitriadis, Georgios; De Reijke, Theo

    2013-07-01

    Biopsy of the prostate is a common procedure with minor complications that are usually self-limited. However, if one considers that millions of men undergo biopsy worldwide, one realizes that although complication rate is low, the number of patients suffering from biopsy complications should not be underestimated and can be a clinically relevant problem for healthcare professionals. In this review, the authors present diagnosis and management of postbiopsy of prostate complications. Bleeding is the most common complication observed after prostate biopsy, but the use of aspirin or nonsteroidal anti-inflammatory drugs is not an absolute contraindication to prostate biopsy. Emerging resistance to ciprofloxacin is the most probable cause of the increasing risk of infectious complications after prostate biopsy. Even though extremely rare, fatal complications are possible and were described in case reports.

  11. Analysis of bone biopsies.

    PubMed

    Goodrich, J A; Difiore, R J; Tippens, J K

    1983-11-01

    The orthopedic surgeon is frequently confronted with the decision of when to perform a bone biopsy and whether to do a needle biopsy or an open biopsy. Frequently consultations are received from other services requesting bone biopsies with questionable indications. The indications and contraindications for performing bone biopsies are discussed as well as advantages and disadvantages of either closed or open technique. Four selective cases are discussed with illustrations. The challenge of undiagnosed osseous lesions is best met by rational evaluation of each individual case and coordinated with the team effort of the primary care physician, surgeon, pathologist, and radiologist. The decision for either an open or closed biopsy technique must be based on the experience and skills of the surgeon and pathologist.

  12. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C

    PubMed Central

    Marzahn, Melissa R.; Hayner, Jaclyn N.; Meyer, Jennifer A.; Bloom, Linda B.

    2014-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+ family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the S. cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway. PMID:25450506

  13. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C.

    PubMed

    Marzahn, Melissa R; Hayner, Jaclyn N; Meyer, Jennifer A; Bloom, Linda B

    2015-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the Saccharomyces cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway.

  14. Utility of synovial biopsy

    PubMed Central

    2009-01-01

    Synovial biopsies, gained either by blind needle biopsy or minimally invasive arthroscopy, offer additional information in certain clinical situations where routine assessment has not permitted a certain diagnosis. In research settings, synovial histology and modern applications of molecular biology increase our insight into pathogenesis and enable responses to treatment with new therapeutic agents to be assessed directly at the pathophysiological level. This review focuses on the diagnostic usefulness of synovial biopsies in the light of actual developments. PMID:19951395

  15. Biopsies in oncology.

    PubMed

    de Bazelaire, C; Coffin, A; Cohen, S; Scemama, A; de Kerviler, E

    2014-01-01

    Imaging-guided percutaneous biopsies in patients in oncology provide an accurate diagnosis of malignant tumors. Percutaneous biopsy results are improved by correct use of sampling procedures. The risks of percutaneous biopsy are low and its complications are generally moderate. These risks can be reduced using aids such as blund tip introducers, hydrodissection and correct patient positioning. The multidisciplinary team meetings dialogue between oncologist, surgeon and radiologist correctly defines the indications in order to improve the treatment strategies.

  16. Colposcopy - directed biopsy

    MedlinePlus

    ... squamous cells - colposcopy; Pap smear - colposcopy; HPV - colposcopy; Human papilloma virus - colposcopy; Cervix - colposcopy; Colposcopy Images Female reproductive anatomy Colposcopy-directed biopsy Uterus References American College of ...

  17. Patch-clamping Drosophila sensory neurons.

    PubMed

    Kucher, Volodymyr; Eaton, Benjamin A; Stockand, James D; Boiko, Nina

    2013-01-01

    Electrophysiological studies provide essential clues about the regulation and physiological function of ion channel proteins. Probing ion channel activity in vivo, though, often is challenging. This can limit the usefulness of such model organisms as Drosophila for electrophysiological studies. This is unfortunate because these genetically tractable organisms represent powerful research tools that facilitate elaboration of complex questions of physiology. Here, we describe a recently developed method for recording ion channel activity in Drosophila sensory neurons. This approach is based on patch-clamping primary neuron cultures from Drosophila embryos. Such cultures allow the study of ion channels in different genetic backgrounds. In addition to describing how to prepare a primary neuronal cell culture from Drosophila embryos, we discuss, as an example of utility, analysis of Na(+) currents in cultured class IV multidendritic (md) sensory neurons with the patch clamp technique. Excitability of md sensory neurons, manifested as action potential firing, is revealed with whole-cell current-clamping. Voltage-clamping class IV md neurons revealed the activity of the voltage-gated Na(+) channel, paralytic. Moreover, challenging class IV md neurons with acidic pH activates acid-sensing inward Na(+) currents. Genetic manipulation of Drosophila combined with this electrophysiological readout of activity identifies pickpocket1 (Ppk1), a member of the Deg/ENaC channel family, as responsible for conducting an acid-sensing Na(+) current in class IV md sensory neurons.

  18. Limit analysis of pipe clamps. Revision 1

    SciTech Connect

    Flanders, H.E. Jr.

    1990-12-31

    The Service Level D (faulted) load capacity of a conventional three-bolt pipe-clamp based upon the limit analysis method is presented. The load distribution, plastic hinge locations, and collapse load are developed for the lower bound limit load method. The results of the limit analysis are compared with the manufacturer`s rated loads. 3 refs.

  19. Patch-clamp amplifiers on a chip.

    PubMed

    Weerakoon, Pujitha; Culurciello, Eugenio; Yang, Youshan; Santos-Sacchi, Joseph; Kindlmann, Peter J; Sigworth, Fred J

    2010-10-15

    We present the first, fully integrated, two-channel implementation of a patch-clamp measurement system. With this "PatchChip" two simultaneous whole-cell recordings can be obtained with rms noise of 8pA in a 10kHz bandwidth. The capacitance and series-resistance of the electrode can be compensated up to 10pF and 100MΩ respectively under computer control. Recordings of hERG and Na(v) 1.7 currents demonstrate the system's capabilities, which are on par with large, commercial patch-clamp instrumentation. By reducing patch-clamp amplifiers to a millimeter size micro-chip, this work paves the way to the realization of massively parallel, high-throughput patch-clamp systems for drug screening and ion-channel research. The PatchChip is implemented in a 0.5μm silicon-on-sapphire process; its size is 3×3mm(2) and the power consumption is 5mW per channel with a 3.3V power supply.

  20. Π-Clamp-mediated cysteine conjugation.

    PubMed

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J; Santos, Michael S; Van Voorhis, Troy; Pentelute, Bradley L

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the 'π-clamp', that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  1. Patch-clamp amplifiers on a chip

    PubMed Central

    Weerakoon, Pujitha; Culurciello, Eugenio; Yang, Youshan; Santos-Sacchi, Joseph; Kindlmann, Peter J.; Sigworth, Fred J.

    2010-01-01

    We present the first, fully-integrated, two-channel implementation of a patch-clamp measurement system. With this “PatchChip” two simultaneous whole-cell recordings can be obtained with rms noise of 8 pA in a 10 kHz bandwidth. The capacitance and series-resistance of the electrode can be compensated up to 10 pF and 100 MΩ respectively under computer control. Recordings of hERG and Nav 1.7 currents demonstrate the system's capabilities, which are on par with large, commercial patch-clamp instrumentation. By reducing patch-clamp amplifiers to a millimeter size micro-chip, this work paves the way to the realization of massively-parallel, high-throughput patch-clamp systems for drug screening and ion-channel research. The PatchChip is implemented in a 0.5 μm silicon-on-sapphire process; its size is 3 × 3 mm2 and the power consumption is 5 mW per channel with a 3.3 V power supply. PMID:20637803

  2. Clamp and Gas Nozzle for TIG Welding

    NASA Technical Reports Server (NTRS)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  3. The Native Kidney Biopsy: Update and Evidence for Best Practice

    PubMed Central

    Mocanu, Michaela; Berns, Jeffrey S.

    2016-01-01

    The kidney biopsy is the gold standard in the diagnosis and management of many diseases. Since its introduction in the 1950s, advancements have been made in biopsy technique to improve diagnostic yield while minimizing complications. Here, we review kidney biopsy indications, techniques, and complications in the modern era. We also discuss patient populations in whom special consideration must be given when considering a kidney biopsy and the important role that the kidney biopsy plays in nephrology training. These data are presented to develop best practice strategies for this essential procedure. PMID:26339068

  4. The Native Kidney Biopsy: Update and Evidence for Best Practice.

    PubMed

    Hogan, Jonathan J; Mocanu, Michaela; Berns, Jeffrey S

    2016-02-05

    The kidney biopsy is the gold standard in the diagnosis and management of many diseases. Since its introduction in the 1950s, advancements have been made in biopsy technique to improve diagnostic yield while minimizing complications. Here, we review kidney biopsy indications, techniques, and complications in the modern era. We also discuss patient populations in whom special consideration must be given when considering a kidney biopsy and the important role that the kidney biopsy plays in nephrology training. These data are presented to develop best practice strategies for this essential procedure.

  5. Dynamics and Stability of Pinned-Clamped and Clamped-Pinned Cylindrical Shells Conveying Fluid

    NASA Astrophysics Data System (ADS)

    Misra, A. K.; Wong, S. S. T.; Païdoussis, M. P.

    2001-11-01

    The paper examines the dynamics and stability of fluid-conveying cylindrical shells having pinned-clamped or clamped-pinned boundary conditions, where ``pinned'' is an abbreviation for ``simply supported''. Flügge's equations are used to describe the shell motion, while the fluid-dynamic perturbation pressure is obtained utilizing the linearized potential flow theory. The solution is obtained using two methods - the travelling wave method and the Fourier-transform approach. The results obtained by both methods suggest that the negative damping of the clamped-pinned systems and positive damping of the pinned-clamped systems, observed by previous investigators for any arbitrarily small flow velocity, are simply numerical artefacts; this is reinforced by energy considerations, in which the work done by the fluid on the shell is shown to be zero. Hence, it is concluded that both systems are conservative.

  6. The Anion Paradox in Sodium Taste Reception: Resolution by Voltage-Clamp Studies

    NASA Astrophysics Data System (ADS)

    Ye, Qing; Heck, Gerard L.; Desimone, John A.

    1991-11-01

    Sodium salts are potent taste stimuli, but their effectiveness is markedly dependent on the anion, with chloride yielding the greatest response. The cellular mechanisms that mediate this phenomenon are not known. This "anion paradox" has been resolved by considering the field potential that is generated by restricted electrodiffusion of the anion through paracellular shunts between taste-bud cells. Neural responses to sodium chloride, sodium acetate, and sodium gluconate were studied while the field potential was voltage-clamped. Clamping at electronegative values eliminated the anion effect, whereas clamping at electropositive potentials exaggerated it. Thus, field potentials across the lingual epithelium modulate taste reception, indicating that the functional unit of taste reception includes the taste cell and its paracellular microenvironment.

  7. Mechanical properties of a lap joint under uniform clamping pressure

    NASA Technical Reports Server (NTRS)

    Diller, S. V.; Metherell, A. F.

    1969-01-01

    Equations were derived for the load deflection relations, the energy dissipation per cycle, and the instantaneous rate of dissipation for a lap joint idealized as two overlapping plates clamped together under a uniform clamping pressure.

  8. Clamp on ultrasonic instruments in subsea applications

    SciTech Connect

    Haugen, S.; Hodgson, S.; Upchurch, J.; McMahan, J.; Hazelrigg, K.; Mundorff, J.

    1995-12-01

    Monitoring of solids flow in pipelines has until recently required pipework intervention in order to insert probes and switches. Both sand particles and cleaning pigs are by nature destructive to these directly exposed detectors due to erosion and inertia. The instruments presented in this paper provide a superior alternative in ultrasonic clamp-on technology requiring only superficial pipework installation. Wells can now be operated efficiently in a way that minimizes the risk of erosion and collapse. Pigging operations can be monitored both by on-line pig detection and debris monitoring thereby allowing a safe and optimized survey to take place. The non-intrusive clamp-on concept raises standards in instrument reliability, durability and measurement performance.

  9. Towards a Dynamic Clamp for Neurochemical Modalities

    PubMed Central

    Rivera, Catalina Maria; Kwon, Hyuck-Jin; Hashmi, Ali; Yu, Gan; Zhao, Jiheng; Gao, Jianlong; Xu, Jie; Xue, Wei; Dimitrov, Alexander G.

    2015-01-01

    The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells' chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators), to register the concentrations with embedded nanosensors and use the processed signals as an input to simulations of a neural cell. The ultimate goal of this project is to close the loop and provide sensor signals to the microfluidic lab-on-a-chip to mimic the interaction of the simulated cell with other cells in its chemical environment. PMID:25946635

  10. Mechanical and metallurgical properties of carotid artery clamps.

    PubMed

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  11. π-Clamp-mediated cysteine conjugation

    NASA Astrophysics Data System (ADS)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  12. Temperature-Controlled Clamping and Releasing Mechanism

    NASA Technical Reports Server (NTRS)

    Rosing, David; Ford, Virginia

    2005-01-01

    A report describes the development of a mechanism that automatically clamps upon warming and releases upon cooling between temperature limits of approx. =180 K and approx. =293 K. The mechanism satisfied a need specific to a program that involved repeated excursions of a spectrometer between a room-temperature atmospheric environment and a cryogenic vacuum testing environment. The mechanism was also to be utilized in the intended application of the spectrometer, in which the spectrometer would be clamped for protection during launch of a spacecraft and released in the cold of outer space to allow it to assume its nominal configuration for scientific observations. The mechanism is passive in the sense that its operation does not depend on a control system and does not require any power other than that incidental to heating and cooling. The clamping and releasing action is effected by bolt-preloaded stacks of shape-memory-alloy (SMA) cylinders. In designing this mechanism, as in designing other, similar SMA mechanisms, it was necessary to account for the complex interplay among thermal expansion, elastic and inelastic deformation under load, and SMA thermomechanical properties.

  13. Carbon nanotube-clamped metal atomic chain

    PubMed Central

    Tang, Dai-Ming; Yin, Li-Chang; Li, Feng; Liu, Chang; Yu, Wan-Jing; Hou, Peng-Xiang; Wu, Bo; Lee, Young-Hee; Ma, Xiu-Liang; Cheng, Hui-Ming

    2010-01-01

    Metal atomic chain (MAC) is an ultimate one-dimensional structure with unique physical properties, such as quantized conductance, colossal magnetic anisotropy, and quantized magnetoresistance. Therefore, MACs show great potential as possible components of nanoscale electronic and spintronic devices. However, MACs are usually suspended between two macroscale metallic electrodes; hence obvious technical barriers exist in the interconnection and integration of MACs. Here we report a carbon nanotube (CNT)-clamped MAC, where CNTs play the roles of both nanoconnector and electrodes. This nanostructure is prepared by in situ machining a metal-filled CNT, including peeling off carbon shells by spatially and elementally selective electron beam irradiation and further elongating the exposed metal nanorod. The microstructure and formation process of this CNT-clamped MAC are explored by both transmission electron microscopy observations and theoretical simulations. First-principles calculations indicate that strong covalent bonds are formed between the CNT and MAC. The electrical transport property of the CNT-clamped MAC was experimentally measured, and quantized conductance was observed. PMID:20427743

  14. π-Clamp Mediated Cysteine Conjugation

    PubMed Central

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; Van Voorhis, Troy; Pentelute, Bradley L.

    2016-01-01

    Site-selective functionalization of complex molecules is a grand challenge in chemistry. Protecting groups or catalysts must be used to selectively modify one site among many that are similarly reactive. General strategies are rare such the local chemical environment around the target site is tuned for selective transformation. Here we show a four amino acid sequence (Phe-Cys-Pro-Phe), which we call the “π-clamp”, tunes the reactivity of its cysteine thiol for the site-selective conjugation with perfluoroaromatic reagents. We used the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues (e.g. antibodies and cysteine-based enzymes), which was impossible with prior cysteine modification methods. The modified π-clamp antibodies retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates (ADCs) for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach for site-selective chemistry and provides opportunities to modify biomolecules for research and therapeutics. PMID:26791894

  15. Single molecule study of a processivity clamp sliding on DNA

    SciTech Connect

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  16. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  17. 33 CFR 183.532 - Clips, straps, and hose clamps.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Clips, straps, and hose clamps... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.532 Clips, straps, and hose clamps. (a) Each clip, strap, and hose clamp must: (1) Be made from a...

  18. Damping mechanisms of single-clamped and prestressed double-clamped resonant polymer microbeams

    NASA Astrophysics Data System (ADS)

    Schmid, S.; Hierold, C.

    2008-11-01

    In this article, an investigation of the damping mechanisms of resonant single- and double-clamped polymer microbeams for a frequency range from 10 kHz to 5 MHz is presented. The suspended structures are made of SU-8, an epoxy-type photoresist, by means of a sacrificial layer technique. The vibration was measured with a laser-Doppler vibrometer in high vacuum at different temperatures and at atmospheric pressure. The influence of air damping in rarefied air was investigated and the intrinsic damping mechanisms were determined in high vacuum (p <0.05 Pa). After excluding a variety of possible damping factors, the dominant intrinsic dissipation mechanism of the single-clamped microbeams was understood to be the material damping with maximum quality factors (Q) of around 70 at 20 °C. Quality factors of up to 720 at 20 °C were measured for stringlike double-clamped microbeams, which suggest a different intrinsic damping mechanism than material loss. It is shown that internal damping mechanisms due to flexure and elongation have a small impact on the damping of stretched strings. Modeling the clamping loss based on the wave transmission into the suspended anchor plates indicates that it is the dominant intrinsic dissipation in the prestressed double-clamped microresonators. At atmospheric pressure it was shown that at low frequencies the quality factors of single-clamped and stringlike double-clamped microbeams are limited by the squeeze-film air damping. At high frequencies the quality factors are limited by the specific intrinsic damping. In between the two particular regions with a specific dominant damping mechanism the quality factors show a maximum.

  19. Salivary gland biopsy

    MedlinePlus

    Biopsy - salivary gland ... You have several pairs of salivary glands that drain into your mouth: A major pair in front of the ears (parotid glands) Another major pair beneath your jaw (submandibular ...

  20. Nasal mucosal biopsy

    MedlinePlus

    ... The tissue in the nose is normal. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different ... Avoid blowing your nose after the biopsy. Do ...

  1. Lung needle biopsy

    MedlinePlus

    ... if you have certain lung diseases such as emphysema. Usually, a collapsed lung after a biopsy does ... any type Bullae (enlarged alveoli that occur with emphysema) Cor pulmonale (condition that causes the right side ...

  2. Open pleural biopsy

    MedlinePlus

    ... due to a virus, fungus, or parasite Mesothelioma Tuberculosis Risks There is a slight chance of: Air ... More Metastatic pleural tumor Pleural needle biopsy Pulmonary tuberculosis Tumor Review Date 11/4/2014 Updated by: ...

  3. Lymph node biopsy

    MedlinePlus

    ... Performed The test is used to diagnose cancer, sarcoidosis, or an infection (such as tuberculosis): When you ... of lymph nodes and other organs and tissues ( sarcoidosis ) Risks Lymph node biopsy may result in any ...

  4. Mediastinoscopy with biopsy

    MedlinePlus

    ... procedure is also done for certain infections (tuberculosis, sarcoidosis) and autoimmune disorders . Normal Results Biopsies of lymph ... Hodgkin disease Lung cancer Lymphoma or other tumors Sarcoidosis The spread of disease from one body part ...

  5. Percutaneous CT-guided needle biopsies of musculoskeletal tumors: a 5-year analysis of non-diagnostic biopsies.

    PubMed

    Chang, Connie Y; Huang, Ambrose J; Bredella, Miriam A; Torriani, Martin; Halpern, Elkan F; Rosenthal, Daniel I; Springfield, Dempsey S

    2015-12-01

    To study non-diagnostic CT-guided musculoskeletal biopsies and take steps to minimize them. Specifically we asked: (1) What malignant diagnoses have a higher non-diagnostic rate? (2) What factors of a non-diagnostic biopsy may warrant more aggressive pursuit? (3) Do intra-procedural frozen pathology (FP) or point-of-care (POC) cytology reduce the non-diagnostic biopsy rate? This study was IRB-approved and HIPAA-compliant. We retrospectively reviewed 963 consecutive CT-guided musculoskeletal biopsies. We categorized pathology results as malignant, benign, or non-diagnostic and recorded use of FP or POC cytology. Initial biopsy indication, final diagnosis, method of obtaining the final diagnosis of non-diagnostic biopsies, age of the patient, and years of biopsy attending experience were recorded. Groups were compared using Pearson's χ(2) test or Fisher's exact test. In all, 140 of 963 (15%) biopsies were non-diagnostic. Lymphoma resulted in more non-diagnostic biopsies (P < 0.0001). While 67% of non-diagnostic biopsies yielded benign diagnoses, 33% yielded malignant diagnoses. Patients whose percutaneous biopsy was indicated due to the clinical context without malignancy history almost always generated benign results (96%). Whereas 56% of biopsies whose indication was an imaging finding of a treatable lesion were malignant, 20% of biopsies whose indication was a history of malignancy were malignant. There was no statistically significant difference in the nondiagnostic biopsy rates of pediatric versus adult patients (P = 0.8) and of biopsy attendings with fewer versus more years of experience (P = 0.5). The non-diagnostic rates of biopsies with FP (8%), POC cytology (25%), or neither (24%) were significantly different (P < 0.0001). Lymphoma is the malignant diagnosis most likely to result in a non-diagnostic biopsy. If the clinical and radiologic suspicion for malignancy is high, repeat biopsy is warranted. If the clinical context suggests a benign

  6. Stereotactic core biopsy: Comparison of 11 gauge with 8 gauge vacuum assisted breast biopsy.

    PubMed

    Venkataraman, Shambhavi; Dialani, Vandana; Gilmore, Hannah L; Mehta, Tejas S

    2012-10-01

    The compare the performance and ability to obtain a correct diagnosis on needle biopsy between 11 gauge and 8 gauge vacuum assisted biopsy devices. Hospital records of all consecutive stereotactic core biopsies performed over five years were retrospectively reviewed in compliance Health Insurance Portability and Accountability Act (HIPPA) policy and with approval from the hospital institutional review board (IRB). Pathology from core biopsy was compared with surgical pathology and/or imaging follow-up. A histological underestimation was defined if the surgical excision yielded a higher grade on pathology which changed management. 828 needle core biopsies (47.5%, 393/828 with 11 gauge and 52.5%, 435/828 with 8 gauge) yielded 471 benign, 153 high risk and 204 malignant lesions. 30/193 (15.5%) 11 gauge lesions and 16/185 (8.6%) 8 gauge lesions demonstrated higher grade pathology on surgical excision. The difference in the rates of the number of correct diagnoses on core needle biopsy between 11 gauge (363/393, 92.4%) and 8 gauge (419/435, 96.3%) based on either surgical or clinical/imaging follow up and the difference in the number of discordant benign core biopsies between 11 (17/217, 7.8%) and 8 gauge (4/254, 1.6%) necessitating a surgical biopsy was significant (P=0.013; P=0.001). Although there were more underestimations with the 11 gauge (25/193, 13.0%) than 8 gauge (15/185, 8.1%) needle, this was not significant. Our study demonstrates improved performance and increased diagnostic ability of 8 gauge needle over 11 gauge in obtaining a correct diagnosis on needle biopsy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Timing of umbilical cord clamping of term infants.

    PubMed

    Ceriani Cernadas, José María

    2017-04-01

    For at least over 200 years, multiple controversies have arisen around the timing of umbilical cord clamping. In the past decades, early cord clamping (within the first 15 seconds) had markedly prevailed. Only in the 21st century, randomized controlled trials have demonstrated the benefits of delayed cord clamping (at 2-3 minutes). Delayed cord clamping has been practiced in obstetrics based on the recommendations made by scientific societies and in systematic reviews, which have provided solid evidence to support this practice in term infants. This review describes the most relevant factors supporting the use of delayed cord clamping in term infants. It points out the essential role played by physiological mechanisms which, undoubtedly, allow us to understand the benefits of delayed cord clamping and advise us to wait for what nature has established. Other relevant aspects supporting delayed cord clamping are also described here. Sociedad Argentina de Pediatría.

  8. Testing and evaluation of stretching strain in clamped-clamped beams for energy harvesting

    NASA Astrophysics Data System (ADS)

    Emad, Ahmed; Mahmoud, Mohamed A. E.; Ghoneima, Maged; Dessouky, Mohamed

    2016-11-01

    In this paper, evaluation of stretching strain capabilities to harvest energy from a piezoelectric clamped-clamped beam is theoretically modeled and experimentally tested. The utilization of stretching strain has many advantages as: elimination of any substrate material, and the simple electrode configuration. The doubly clamped structure exhibits a highly nonlinear frequency response (Hardening Duffing) that widens the bandwidth during the frequency up-ward sweep. The wide bandwidth makes it suitable for practical applications. A design of 53.5 {{mm}}3 (29.7 {{mm}}3 piezoelectric material + 23.8 {{mm}}3 proof mass) energy harvester was tested using PVDF (polyvinylidene fluoride) that can generate up to 15 μW from vibrations of 0.5{g} at 128 {Hz} and 2 MΩ load. The design can also generate up to 41 μ {{W}} from vibrations of 1{g} at 140 {Hz} and 2 MΩ load.

  9. The Clamp Loader Assembles the β Clamp onto Either a 3′ or 5′ Primer Terminus

    PubMed Central

    Park, Mee Sook; O'Donnell, Mike

    2009-01-01

    Clamp loaders assemble sliding clamps onto 3′ primed sites for DNA polymerases. Clamp loaders are thought to be specific for a 3′ primed site, and unable to bind a 5′ site. We demonstrate here that the Escherichia coli γ complex clamp loader can load the β clamp onto a 5′ primed site, although with at least 20-fold reduced efficiency relative to loading at a 3′ primed site. Preferential clamp loading at a 3′ site does not appear to be due to DNA binding, as the clamp loader forms an avid complex with β at a 5′ site. Preferential loading at a 3′ versus a 5′ site occurs at the ATP hydrolysis step, needed to close the ring around DNA. We also address DNA structural features that are recognized for preferential loading at a 3′ site. Although the single-stranded template strand extends in opposite directions from 3′ and 5′ primed sites, thus making it a favorite candidate for distinguishing between 3′ and 5′ sites, the single-strand polarity at a primed template junction does not determine 3′ site selection for clamp loading. Instead, we find that clamp loader recognition of a 3′ site lies in the duplex portion of the primed site, not the single-strand portion. We present evidence that the β clamp facilitates its own loading specificity for a 3′ primed site. Implications to eukaryotic clamp loader complexes are proposed. PMID:19759020

  10. Analysis and testing of the DIII-D ohmic heating coil lead repair clamp

    SciTech Connect

    Reis, E.E.; Anderson, P.M.; Chin, E.; Robinson, J.I.

    1997-11-01

    DIII-D has been operating for the last year with limited volt-second capabilities due to structural failure of a conductor lead to one of the ohmic heating (OH) solenoids. The conductor failure was due to poor epoxy impregnation of the overwrap of the lead pack, resulting in copper fatigue and a water leak. A number of structural analyses were performed to assist in determining the failure scenario and to evaluate various repair options. A fatigue stress analysis of the leads with a failed epoxy overwrap indicated crack initiation after 1,000 cycles at the maximum operating conditions. The failure occurred in a very inaccessible area which restricted design repair options to concepts which could be implemented remotely. Several design options were considered for repairing the lead so that it can sustain the loads for 7.5 Vs conditions at full toroidal field. A clamp, along with preloaded banding straps and shim bags, provides a system that guarantees that the stress at the crack location is always compressive and prevents further crack growth in the conductor. Due to the limited space available for the repair, it was necessary to design the clamp system to operate at the material yield stress. The primary components of the clamp system were verified by load tests prior to installation. The main body of the clamp contains a load cell and potentiometer for monitoring the load-deflection characteristics of the clamp and conductors during plasma operation. Strain gages provides redundant instrumentation. If required, the preload on the conductors can be increased remotely by a special wrench attached to the clamp assembly.

  11. Current concepts in the biopsy of musculoskeletal tumors.

    PubMed

    Traina, Francesco; Errani, Costantino; Toscano, Angelo; Pungetti, Camilla; Fabbri, Daniele; Mazzotti, Antonio; Donati, Davide; Faldini, Cesare

    2015-01-07

    A musculoskeletal tumor biopsy can involve fine needle aspiration, core needle biopsy, or incisional biopsy. Controversy regarding the diagnostic yield of these biopsy techniques continues. The purpose of this article is to summarize the current concepts in the biopsy of musculoskeletal tumors. We performed a literature review of clinical articles reporting on the biopsy of bone and soft-tissue primary tumors. Clinical articles were excluded on the basis on abstract content if they represented case reports, review or opinion articles, or technique descriptions. Eighteen of the thirty-nine articles that remained were excluded because the results did not indicate the diagnostic accuracy of the various biopsy techniques. Thus, twenty-one articles with diagnostic data on the biopsy of bone and soft-tissue tumors were included in this review. Core needle biopsy appeared to be more accurate than fine needle aspiration, and incisional biopsy appeared to be more accurate than both of these techniques, but the differences did not reach significance. Incisional biopsy was more expensive than the percutaneous biopsy methods. In deep musculoskeletal tumors, incorporation of ultrasonography or computed tomography for guidance is easy and safe and can be useful for increasing the accuracy of the biopsy. Advantages of a percutaneous technique compared with an incisional one are the low risk of contamination and the minimally invasive nature. Certain anatomic locations and histologic types were associated with diagnostic difficulty. Vertebral tumors had the lowest diagnostic accuracy regardless of the biopsy technique. Myxoid, infection, and round cell histologies were associated with the lowest diagnostic accuracy. The current literature has not clarified the optimal biopsy technique for the diagnosis of bone and soft-tissue tumors. However, core needle biopsy is usually preferable to incisional biopsy because of the low risk of contamination and the low cost. In addition, the

  12. Laser-assisted patch clamping: a methodology

    NASA Technical Reports Server (NTRS)

    Henriksen, G. H.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Laser microsurgery can be used to perform both cell biological manipulations, such as targeted cell ablation, and molecular genetic manipulations, such as genetic transformation and chromosome dissection. In this report, we describe a laser microsurgical method that can be used either to ablate single cells or to ablate a small area (1-3 microns diameter) of the extracellular matrix. In plants and microorganisms, the extracellular matrix consists of the cell wall. While conventional patch clamping of these cells, as well as of many animal cells, requires enzymatic digestion of the extracellular matrix, we illustrate that laser microsurgery of a portion of the wall enables patch clamp access to the plasma membrane of higher plant cells remaining situated in their tissue environment. What follows is a detailed description of the construction and use of an economical laser microsurgery system, including procedures for single cell and targeted cell wall ablation. This methodology will be of interest to scientists wishing to perform cellular or subcellular ablation with a high degree of accuracy, or wishing to study how the extracellular matrix affects ion channel function.

  13. Laser-assisted patch clamping: a methodology

    NASA Technical Reports Server (NTRS)

    Henriksen, G. H.; Assmann, S. M.; Evans, M. L. (Principal Investigator)

    1997-01-01

    Laser microsurgery can be used to perform both cell biological manipulations, such as targeted cell ablation, and molecular genetic manipulations, such as genetic transformation and chromosome dissection. In this report, we describe a laser microsurgical method that can be used either to ablate single cells or to ablate a small area (1-3 microns diameter) of the extracellular matrix. In plants and microorganisms, the extracellular matrix consists of the cell wall. While conventional patch clamping of these cells, as well as of many animal cells, requires enzymatic digestion of the extracellular matrix, we illustrate that laser microsurgery of a portion of the wall enables patch clamp access to the plasma membrane of higher plant cells remaining situated in their tissue environment. What follows is a detailed description of the construction and use of an economical laser microsurgery system, including procedures for single cell and targeted cell wall ablation. This methodology will be of interest to scientists wishing to perform cellular or subcellular ablation with a high degree of accuracy, or wishing to study how the extracellular matrix affects ion channel function.

  14. Breast Biopsy System

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Charge Coupled Devices (CCDs) are high technology silicon chips that connect light directly into electronic or digital images, which can be manipulated or enhanced by computers. When Goddard Space Flight Center (GSFC) scientists realized that existing CCD technology could not meet scientific requirements for the Hubble Space Telescope Imagining Spectrograph, GSFC contracted with Scientific Imaging Technologies, Inc. (SITe) to develop an advanced CCD. SITe then applied many of the NASA-driven enhancements to the manufacture of CCDs for digital mammography. The resulting device images breast tissue more clearly and efficiently. The LORAD Stereo Guide Breast Biopsy system incorporates SITe's CCD as part of a digital camera system that is replacing surgical biopsy in many cases. Known as stereotactic needle biopsy, it is performed under local anesthesia with a needle and saves women time, pain, scarring, radiation exposure and money.

  15. Comparative Effectiveness of Frame-based, Frameless and Intraoperative MRI Guided Brain Biopsy Techniques

    PubMed Central

    Lu, Yi; Yeung, Cecil; Radmanesh, Alireza; Wiemann, Robert; Black, Peter M.; Golby, Alexandra J.

    2015-01-01

    Objective Intraoperative MRI (IoMRI) guided brain biopsy provides a real time visual feedback of the lesion that is sampled during surgery. The objective of the study is to compare the diagnostic yield and safety profiles of ioMRI needle brain biopsy with two traditional brain biopsy methods: frame-based and frameless stereotactic brain biopsies. Methods A retrospective analysis from 288 consecutive needle brain biopsies in 277 patients undergoing stereotactic brain biopsy with any of the three biopsy methods at Brigham and Women's Hospital from 2000 to 2008 was performed. Variables such as age, sex, history of radiation and previous surgery, pathology results, complications and postoperative stays were analyzed. Results Over the course of eight years, 288 brain biopsies were performed. 253 (87.8%) biopsies yielded positive diagnostic tissue. Young age (<40 years), history of brain radiation or surgery were significant negative predictors for a positive biopsy diagnostic yield. Excluding patients with prior radiation or surgeries, no significant difference in diagnostic yield was detected among the three groups, with frame-based, frameless and ioMRI guided needle biopsies yield 96.9%, 91.8% and 89.9% positive diagnostic yield, respectively. 19 biopsies (6.6%) were complicated by serious adverse events. The ioMRI-guided brain biopsy was associated with less serious adverse events and the shortest postoperative hospital stay. Conclusions Frame-based, frameless stereotactic and ioMRI guided brain needle biopsy have comparable diagnostic yield for patients with no prior treatments (either radiation or surgery). IoMRI guided brain biopsy is associated with fewer serious adverse events and shorter hospital stay. PMID:25088233

  16. Complications of the percutaneous kidney biopsy.

    PubMed

    Whittier, William L

    2012-05-01

    Percutaneous kidney biopsy is an integral part of a nephrologist's practice. It has helped to define nephrology as a subspecialty. When indicated, it is a necessary procedure to help patients, as it allows for diagnostic, prognostic, and therapeutic information. Although very safe, this procedure can give rise to complications, mainly related to bleeding. Since its development in the 1950s, modifications have been made to the approach and the technique, which have improved the diagnostic yield while keeping it a safe procedure. Alterations to the standard approach may be necessary if risk factors for bleeding are present. In addition, obesity, pregnancy, and solitary kidney biopsy are all special circumstances that change the procedure itself or the risk of the procedure. Today, kidney biopsy is a vital procedure for the nephrologist: clinically relevant, safe, and effective.

  17. Core needle biopsies and surgical excision biopsies in the diagnosis of lymphoma-experience at the Lymph Node Registry Kiel.

    PubMed

    Johl, Alice; Lengfelder, Eva; Hiddemann, Wolfgang; Klapper, Wolfram

    2016-08-01

    Current guidelines of the European Society of Medical Oncology recommend surgical excision biopsies of lymph nodes for the diagnosis of lymphoma whenever possible. However, core needle biopsies are increasingly used. We aimed to understand the common practice to choose the method of biopsy in Germany. Furthermore, we wanted to understand performance of surgical excision and core needle biopsies of lymph nodes in the diagnosis of lymphoma. The files of 1510 unselected, consecutive lymph node specimens from a consultation center for lymphoma diagnosis were analyzed. Core needle biopsies were obtained frequently from lymph nodes localized in mediastinal, abdominal, retroperitoneal, or thoracic regions. Patients undergoing core needle biopsies were significantly older and suffered significantly more often from lymphoma than patients undergoing surgical excision biopsies. Although more immunohistochemical tests were ordered by the pathologist for core needle biopsies specimens than for surgical excision biopsies specimens, core needle biopsies did not yield a definite diagnosis in 8.3 % of cases, compared to 2.8 % for SEB (p = 0.0003). Restricting the analysis to cases with a final diagnosis of follicular lymphoma or diffuse large B-cell lymphoma, core needle biopsies identified a simultaneous low- and high-grade lymphoma (transformation) in 3.3 % of cases, compared to 7.6 % for surgical excision biopsies (p = 0.2317). In Germany, core needle biopsies are preferentially used in elderly patients with a high likelihood of suffering from lymphoma. Core needle appeared inferior to surgical excision biopsies at providing a definite diagnosis and at identifying multiple lymphoma differentiations and transformation.

  18. Frameless robotic stereotactic biopsies: a consecutive series of 100 cases.

    PubMed

    Lefranc, Michel; Capel, Cyrille; Pruvot-Occean, Anne-Sophie; Fichten, Anthony; Desenclos, Christine; Toussaint, Patrick; Le Gars, Daniel; Peltier, Johann

    2015-02-01

    Stereotactic biopsy procedures are an everyday part of neurosurgery. The procedure provides an accurate histological diagnosis with the least possible morbidity. Robotic stereotactic biopsy needs to be an accurate, safe, frameless, and rapid technique. This article reports the clinical results of a series of 100 frameless robotic biopsies using a Medtech ROSA device. The authors retrospectively analyzed their first 100 frameless stereotactic biopsies performed with the robotic ROSA device: 84 biopsies were performed by frameless robotic surface registration, 7 were performed by robotic bone fiducial marker registration, and 9 were performed by scalp fiducial marker registration. Intraoperative flat-panel CT scanning was performed concomitantly in 25 cases. The operative details of the robotic biopsies, the diagnostic yield, and mortality and morbidity data observed in this series are reported. A histological diagnosis was established in 97 patients. No deaths or permanent morbidity related to surgery were observed. Six patients experienced transient neurological worsening. Six cases of bleeding within the lesion or along the biopsy trajectory were observed on postoperative CT scans but were associated with transient clinical symptoms in only 2 cases. Stereotactic surgery was performed with patients in the supine position in 93 cases and in the prone position in 7 cases. The use of fiducial markers was reserved for posterior fossa biopsy via a transcerebellar approach, via an occipital approach, or for pediatric biopsy. ROSA frameless stereotactic biopsies appear to be accurate and safe robotized frameless procedures.

  19. [Efficacy and safety of renal biopsy in children performed with an automatic biopsy device under control of ultrasonographic imaging].

    PubMed

    Zurowska, A; Kosiak, W; Czarniak, P; Bałasz, I; Marczak, E

    2001-04-01

    The efficacy and safety of kidney biopsy in children performed with an automatic Biopty Gun device under real time ultrasound was analysed. The procedure was performed under sedation during short hospitalisation with ultrasound assessment of complications performed after 24 hours. 98% of 131 biopsies yielded representative material with an average 16 glomeruli obtained per biopsy. Symptomatic perirenal haematomas were observed in 80%, subcapsular haematomas in 3.8% and arteriovenous fistulas in 4.6% of children on post biopsy ultrasound. They resolved spontaneously in all patients. Real time ultrasound guidance with the use of automatic biopsy devices should become the standard practice for kidney biopsy in children due to its efficacy and safety. The procedure should be performed during short hospitalization to enable ultrasound monitoring of early complications.

  20. Experimental and numerical analysis of clamped joints in front motorbike suspensions

    NASA Astrophysics Data System (ADS)

    Croccolo, D.; de Agostinis, M.; Vincenzi, N.

    2010-06-01

    Clamped joints are shaft-hub connections used, as an instance, in front motorbike suspensions to lock the steering plates with the legs and the legs with the wheel pin, by means of one or two bolts. The preloading force, produced during the tightening process, should be evaluated accurately, since it must lock safely the shaft, without overcoming the yielding point of the hub. Firstly, friction coefficients have been evaluated on “ad-hoc designed” specimens, by applying the Design of Experiment approach: the applied tightening torque has been precisely related to the imposed preloading force. Then, the tensile state of clamps have been evaluated both via FEM and by leveraging some design formulae proposed by the Authors as function of the preloading force and of the clamp geometry. Finally, the results have been compared to those given by some strain gauges applied on the tested clamps: the discrepancies between numerical analyses, the design formulae and the experimental results remains under a threshold of 10%.

  1. Thyroid gland biopsy (image)

    MedlinePlus

    The thyroid is a gland located in the neck. It is a part of the endocrine (hormone) system, and plays a major role in regulating ... sample of cells is needed from the thyroid gland a fine needle biopsy can be performed. During ...

  2. Biopsy (For Parents)

    MedlinePlus

    ... you understand the procedure and its risks and alternatives and give your permission for it to be performed. The person doing the biopsy will know your child's medical history, but might ask additional questions, such as what medicines your child is taking or whether your child ...

  3. Percutaneous renal tumour biopsy.

    PubMed

    Delahunt, Brett; Samaratunga, Hemamali; Martignoni, Guido; Srigley, John R; Evans, Andrew J; Brunelli, Matteo

    2014-09-01

    The use of percutaneous renal tumour biopsy (RTB) as a diagnostic tool for the histological characterization of renal masses has increased dramatically within the last 30 years. This increased utilization has paralleled advances in imaging techniques and an evolving knowledge of the clinical value of nephron sparing surgery. Improved biopsy techniques using image guidance, coupled with the use of smaller gauge needles has led to a decrease in complication rates. Reports from series containing a large number of cases have shown the non-diagnostic rate of RTB to range from 4% to 21%. Re-biopsy has been shown to reduce this rate, while the use of molecular markers further improves diagnostic sensitivity. In parallel with refinements of the biopsy procedure, there has been a rapid expansion in our understanding of the complexity of renal cell neoplasia. The 2013 Vancouver Classification is the current classification for renal tumours, and contains five additional entities recognized as novel forms of renal malignancy. The diagnosis of tumour morphotype on RTB is usually achievable on routine histology; however, immunohistochemical studies may be of assistance in difficult cases. The morphology of the main tumour subtypes, based upon the Vancouver Classification, is described and differentiating features are discussed. © 2014 John Wiley & Sons Ltd.

  4. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Cromwell, B. K.; Shepherd, S. D.; Pender, C. W.; Wood, B. E.

    1993-01-01

    Infrared hemispherical reflectance measurements that were made on 58 chromic acid anodized tray clamps from LDEF are described. The measurements were made using a hemiellipsoidal mirror reflectometer with interferometer for wavelengths between 2-15 microns. The tray clamps investigated were from locations about the entire spacecraft and provided the opportunity for comparing the effects of atomic oxygen at each location. Results indicate there was essentially no dependence on atomic oxygen fluence for the surfaces studied, but there did appear to be a slight dependence on solar radiation exposure. The reflectances of the front sides of the tray clamps consistently were slightly higher than for the protected rear tray clamp surfaces.

  5. An Optimal Cell Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2004-01-01

    While there are several hardware techniques for the automated patch clamping of cells that describe the equipment apparatus used for patch clamping, very few explain the science behind the actual technique of locating the ideal cell for a patch clamping procedure. We present a machine vision approach to patch clamping cell selection by developing an intelligent algorithm technique that gives the user the ability to determine the good cell to patch clamp in an image within one second. This technique will aid the user in determining the best candidates for patch clamping and will ultimately save time, increase efficiency and reduce cost. The ultimate goal is to combine intelligent processing with instrumentation and controls in order to produce a complete turnkey automated patch clamping system capable of accurately and reliably patch clamping cells with a minimum amount of human intervention. We present a unique technique that identifies good patch clamping cell candidates based on feature metrics of a cell's (x, y) position, major axis length, minor axis length, area, elongation, roundness, smoothness, angle of orientation, thinness and whether or not the cell is only particularly in the field of view. A patent is pending for this research.

  6. Delayed cord clamping and cord gas analysis at birth.

    PubMed

    Xodo, Serena; Xodo, Luigi; Berghella, Vincenzo

    2017-09-16

    Delayed cord clamping for at least 60 seconds in both term and preterm babies is a major recent change in clinical care. Delayed cord clamping has several effects on other possible interventions. One of these is the effect of delayed cord clamping on umbilical artery gas analysis. When indicated, umbilical artery gas analysis can safely be done either with early cord clamping, or, probably most of the times it is necessary, during delayed cord clamping with the cord still unclamped. Paired blood samples (one from the umbilical artery and one from the umbilical vein) can be taken from the pulsating and unclamped cord, immediately after birth, during delayed cord clamping, without any effect on either the accuracy of umbilical artery gas analysis or on the transfusion of blood through delayed cord clamping. Umbilical artery gas analysis should instead not be done after delayed cord clamping, since delayed cord clamping alters several acid-based parameters and lactate values. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Obstetricians' attitudes and beliefs regarding umbilical cord clamping.

    PubMed

    Jelin, Angie C; Kuppermann, Miriam; Erickson, Kristine; Clyman, Ronald; Schulkin, Jay

    2014-09-01

    Although delayed umbilical cord clamping has been demonstrated to reduce the incidence of intraventricular hemorrhage and neonatal sepsis, and decrease the need for neonatal transfusions (without affecting cord pH, Apgar scores or the need for phototherapy), the extent to which this practice is being employed is unknown. We conducted a survey of US obstetricians to assess their attitudes and beliefs about cord clamping. Questionnaires were randomly mailed to members of the American College of Obstetricians and Gynecologists (ACOG), and the Collaborative Ambulatory Research Network (CARN). The data were analyzed using Chi-square and Student t tests. The response rates for the CARN and other ACOG members were 47% and 21%, respectively. Most (88%) responders reported their hospital had no umbilical cord clamping policy. The most frequent response for optimal timing of umbilical cord clamping, regardless of gestational age, was "don't know". Potential for neonatal red blood cell transfusion was the only concern cited as a reason for being somewhat or very inclined to delay umbilical cord clamping (51%). Delayed neonatal resuscitation (76%) was listed as a reason to clamp the cord immediately, despite the paucity of literature to support immediate cord clamping in this cohort. Despite substantial evidence supporting the practice of delayed cord clamping, few institutions have policies regarding this practice. Moreover, obstetricians' beliefs about the appropriate timing for umbilical cord clamping are not consistent with the evidence that demonstrates its beneficial impact on neonatal outcomes.

  8. Re-visiting the trans insertion model for complexin clamping

    PubMed Central

    Krishnakumar, Shyam S; Li, Feng; Coleman, Jeff; Schauder, Curtis M; Kümmel, Daniel; Pincet, Frederic; Rothman, James E; Reinisch, Karin M

    2015-01-01

    We have previously proposed that complexin cross-links multiple pre-fusion SNARE complexes via a trans interaction to function as a clamp on SNARE-mediated neurotransmitter release. A recent NMR study was unable to detect the trans clamping interaction of complexin and therefore questioned the previous interpretation of the fluorescence resonance energy transfer and isothermal titration calorimetry data on which the trans clamping model was originally based. Here we present new biochemical data that underscore the validity of our previous interpretation and the continued relevancy of the trans insertion model for complexin clamping. DOI: http://dx.doi.org/10.7554/eLife.04463.001 PMID:25831964

  9. Comparison of Battery-Powered and Manual Bone Biopsy Systems for Core Needle Biopsy of Sclerotic Bone Lesions.

    PubMed

    Cohen, Micah G; McMahon, Colm J; Kung, Justin W; Wu, Jim S

    2016-05-01

    The purpose of this study was to compare manual and battery-powered bone biopsy systems for diagnostic yield and procedural factors during core needle biopsy of sclerotic bone lesions. A total of 155 consecutive CT-guided core needle biopsies of sclerotic bone lesions were performed at one institution from January 2006 to November 2014. Before March 2012, lesions were biopsied with manual bone drill systems. After March 2012, most biopsies were performed with a battery-powered system and either noncoaxial or coaxial biopsy needles. Diagnostic yield, crush artifact, CT procedure time, procedure radiation dose, conscious sedation dose, and complications were compared between the manual and battery-powered core needle biopsy systems by Fisher exact test and t test. One-way ANOVA was used for subgroup analysis of the two battery-powered systems for procedure time and radiation dose. The diagnostic yield for all sclerotic lesions was 60.0% (93/155) and was significantly higher with the battery-powered system (73.0% [27/37]) than with the manual systems (55.9% [66/118]) (p = 0.047). There was no significant difference between the two systems in terms of crush artifact, procedure time, radiation dose, conscious sedation administered, or complications. In subgroup analysis, the coaxial battery-powered biopsies had shorter procedure times (p = 0.01) and lower radiation doses (p = 0.002) than the coaxial manual systems, but the noncoaxial battery-powered biopsies had longer average procedure times and higher radiation doses than the coaxial manual systems. In biopsy of sclerotic bone lesions, use of a battery-powered bone drill system improves diagnostic yield over use of a manual system.

  10. Thermal stiffening of clamped elastic ribbons

    NASA Astrophysics Data System (ADS)

    Wan, Duanduan; Nelson, David R.; Bowick, Mark J.

    2017-07-01

    We use molecular dynamics to study the vibrations of a thermally fluctuating two-dimensional elastic membrane clamped at both ends. We directly extract the eigenmodes from resonant peaks in the frequency domain of the time-dependent height and measure the dependence of the corresponding eigenfrequencies on the microscopic bending rigidity of the membrane, taking care also of the subtle role of thermal contraction in generating a tension when the projected area is fixed. At finite temperatures we show that the effective (macroscopic) bending rigidity tends to a constant as the bare bending rigidity vanishes, consistent with theoretical arguments that the large-scale bending rigidity of the membrane arises from a strong thermal renormalization of the microscopic bending rigidity. Experimental realizations include covalently bonded two-dimensional atomically thin membranes such as graphene and molybdenum disulfide or soft matter systems such as the spectrin skeleton of red blood cells or diblock copolymers.

  11. Nanoindentation characteristics of clamped freestanding Cu membranes.

    PubMed

    Wang, Tong Hong; Fang, Te-Hua; Kang, Shao-Hui; Lin, Yu-Cheng

    2007-04-04

    This research employed instrumented nanoindentation to address the issue of bending to stretching-induced deformation of clamped freestanding Cu membranes. The experimental results show that indentation-induced plastic deformation only comes into effect at the centre and the indented edge of the Cu membrane when the indenter is applied, while the other locations remain undamaged. A step-by-step evolution was presumed for the time histories of the bending to stretching-induced deformation and for the timing of the significant change in slope of the load-deflection curve. Deformation was deliberately introduced at the transition from the single-point bending indentation to the surface stretching indentation at the impact location touched with the indenter. Good elastic recovery was found at locations away from the indenter. A similar finding can be arrived at by means of finite element analysis.

  12. Pipe lifting hook having clamp assembly

    SciTech Connect

    Codner, J.A.

    1984-06-12

    A pipe lifting hook is provided having a generally ''C'' shaped hook member having an elongated lower portion being insertable within the end of a joint of pipe and having an upper portion positionable above the pipe and provided with lifting connection means. The hook member is frictionally clamped to the pipe by grip shoe means that is movably supported by the upper portion of the hook member and is selectably movable from a released position out of contact with said pipe to a locked position in frictional locking engagement with the outer surface of the pipe. A ratchet mechanism couples said grip shoe means to the upper portion of the hook member and is manually positionable to lock said grip shoe means at said locked position or release said grip shoe means for movement toward said released position thereof.

  13. Clinical results of minimally invasive mitral valve surgery: endoaortic clamp versus external aortic clamp techniques.

    PubMed

    Ius, Fabio; Mazzaro, Enzo; Tursi, Vincenzo; Guzzi, Giorgio; Spagna, Enrico; Vetrugno, Luigi; Bassi, Flavio; Livi, Ugolino

    2009-11-01

    : This study was carried out with the aim of presenting our experience with minimally invasive mitral surgery and compare the endoaortic clamp with the external aortic clamp (EAC) techniques. : Between December 2002 and May 2009, 139 patients (75 men, aged 63 ± 11 years) underwent video-assisted mitral valve surgery through right thoracotomy. Twelve (9%) patients were operated without clamping the aorta, 32 (23%) patients (group A) were operated on by using the endoaortic clamp, and 95 (68%) patients were operated on by using the EAC (group B). There was no significant difference between groups A and B regarding preoperative variables. : Intraoperative procedure-associated problems were experienced in three group A patients (9.3%, two aortic dissections with conversion to sternotomy; one conversion due to bad exposure) and in two group B patients (2%, one conversion to sternotomy for bleeding and one for ascending aorta hematoma). At a mean follow-up of 32 months, 121 patients (97%) were in New York Heart Association class I-II, with satisfactory echocardiographic results. There was one in-hospital and six late deaths (three noncardiac, two cardiac, and one valve related). Five-year actuarial survival was 88% ± 8%. There were three reoperations, one early (<30 days) after complex mitral valve repair, with a 5-year freedom from reoperation of 97% ± 2%. Postoperative levels of myocardial cytonecrosis enzymes as well as the extracorporeal circulation time were significantly lower in group B patients (P < 0.05). : Intraoperative procedure-associated complications with endoclamping combined with an apparently better myocardial protection forced us to change our practice to the more simple and economic EAC technique.

  14. The PCNA-RFC families of DNA clamps and clamp loaders.

    PubMed

    Majka, Jerzy; Burgers, Peter M J

    2004-01-01

    The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.

  15. Gram stain of tissue biopsy

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003453.htm Gram stain of tissue biopsy To use the sharing features on this page, please enable JavaScript. Gram stain of tissue biopsy test involves using crystal violet ...

  16. Ultrasound-Guided Breast Biopsy

    MedlinePlus

    ... Breast Biopsy An ultrasound-guided breast biopsy uses sound waves to help locate a lump or abnormality ... exam. The transducer sends out inaudible, high—frequency sound waves into the body and then listens for ...

  17. Liver biopsy in sheep.

    PubMed

    Hidiroglou, M; Ivan, M

    1993-01-01

    Liver biopsies were performed in the same group of 16 sheep on 8 consecutive wk using an apparatus with a fibre optic continuous light source and a telescope. The sheep were placed in a sternal position on a special table constructed of metal pipes (3.8 cm diameter) and 4.5 cm spacing. Approximately 300 mg of fresh liver sample was removed from each sheep to be analyzed for copper or vitamin E.

  18. Combination Space Station Handrail Clamp and Pointing Device

    NASA Technical Reports Server (NTRS)

    Hughes, Stephen J. (Inventor)

    1999-01-01

    A device for attaching an experiment carrier to a space station handrail is provided. The device has two major components, a clamping mechanism for attachment to a space station handrail, and a pointing carrier on which an experiment package can be mounted and oriented. The handrail clamp uses an overcenter mechanism and the carrier mechanism uses an adjustable preload ball and socket for carrier positioning. The handrail clamp uses a stack of disk springs to provide a spring loaded button. This configuration provides consistent clamping force over a range of possible handrail thicknesses. Three load points are incorporated in the clamping mechanism thereby spreading the clamping load onto three separate points on the handrail. A four bar linkage is used to provide for a single actuation lever for all three load points. For additional safety, a secondary lock consisting of a capture plate and push lock keeps the clamp attached to the handrail in the event of main clamp failure. For the carrier positioning mechanism, a ball in a spring loaded socket uses friction to provide locking torque; however. the ball and socket are torque limited so that the ball ran slip under kick loads (125 pounds or greater). A lead screw attached to disk spring stacks is used to provide an adjustable spring force on the socket. A locking knob is attached to the lead screw to allow for hand manipulation of the lead screw.

  19. OPTIMAL TIMING FOR CLAMPING THE UMBILICAL CORD AFTER BIRTH

    PubMed Central

    Raju, Tonse N. K.; Singal, Nalini

    2013-01-01

    Synopsis This paper provides a brief overview of pros and cons of clamping the cord too early (within seconds) after birth. It also highlights evolving data that suggests that delaying cord clamping for 30–60 seconds after birth is beneficial to the baby and the mother, with no measurable negative effects. PMID:23164185

  20. Nuclear Patch-Clamp Electrophysiology of Ca2+ Channels

    PubMed Central

    Mak, Don-On Daniel; Vais, Horia; Cheung, King-Ho; Foskett, J. Kevin

    2014-01-01

    Patch-clamping the outer or inner nuclear membrane of isolated nuclei is very similar to patch-clamping the plasma membrane of isolated cells. This protocol describes in detail all the steps required to successfully obtain nuclear membrane patches, in various configurations, from both the outer and inner nuclear membranes of isolated nuclei. PMID:24003194

  1. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males...

  2. 21 CFR 876.5160 - Urological clamp for males.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males...

  3. The Value of Endocervical Curettage in Addition to Biopsies in Women Referred to Colposcopy.

    PubMed

    van der Marel, Jacolien; Rodriguez, Agata; Del Pino, Marta; van Baars, Romy; Jenkins, David; van de Sandt, Miekel M; Torné, Aureli; Ordi, Jaume; ter Harmsel, Bram; Verheijen, René H M; Schiffman, Mark; Gage, Julia C; Quint, Wim G V; Wentzensen, Nicolas

    2015-10-01

    Performing endocervical curettage (ECC) at colposcopy may increase the yield of cervical intraepithelial neoplasia grade 2 (CIN2) or worse (CIN2+) compared to biopsies alone. The additional benefit of ECC in detecting CIN2+ was studied in women with lesion-targeted biopsies (low-grade or worse impression) and women with biopsies of normal-appearing cervix (less than low-grade impression). In this subanalysis of a multicenter study, 126 women referred to colposcopy who had an ECC were included. Multiple directed biopsies were taken from lesions, and a nontargeted biopsy was added if fewer than 4 biopsies were collected. Risk strata of CIN2+ were evaluated based on cytology and colposcopic appearance to identify women for whom ECC would be most valuable. The CIN2+ yield of ECC in addition to biopsies was 15 (11.9%) of 126. In women with lesion-targeted biopsies and ECC, the CIN2+ yield of targeted biopsies was 34 (51.5%) of 66, the yield of additional nontargeted biopsies was 1 (1.5%) of 66, and the additional CIN2+ yield of ECC was 5 (7.6%) of 66. The yield in women with nontargeted biopsies only and ECC was 5 (8.3%) 60, and the additional yield for ECC was 10 (16.7%) of 60. Endocervical curettage did not find disease in women with atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion. In women with less than low-grade impression and especially those with unsatisfactory colposcopy, the yield of CIN2+ was higher for ECC compared to nontargeted biopsies. The highest yield of CIN2+ from ECC was observed in women with high-grade squamous intraepithelial lesion and less than low-grade impression, suggesting that disease is higher up in the endocervix in this group.

  4. Ultrasound-guided percutaneous splenic biopsy using an 18-G core biopsy needle: our experience with 52 cases

    PubMed Central

    Dawe, Gemma; Tung, Ken

    2015-01-01

    Objective: The spleen is more commonly affected in multiorgan disease, but alternative sites are selected for biopsy owing to perceived haemorrhage risk. If these sites are inaccessible or, less commonly, the spleen is the only disease site, then splenic biopsy is considered, with most studies using a 20- to 22-G needle. The primary aim of biopsy is to exclude underlying malignancy or to obtain histological analysis in known malignancy, usually lymphoma, when reclassification is required for therapy. We present, to our knowledge, the largest series of 18-G ultrasound-guided splenic core needle biopsy assessing diagnostic and complication rates. Methods: All ultrasound-guided splenic biopsy cases from May 1990 to May 2015 were identified on the radiology information system. Histological diagnosis and complications were identified from laboratory reports, case notes and discharge summaries to assess diagnostic positive and complication rates. Haemorrhages requiring transfusion, embolization or splenectomy, pneumothorax, other significant intra-abdominal injury or death are classified as major complications, whilst conservative haemorrhage management is considered a minor complication. Results: A total of 52 splenic biopsies were performed in 47 patients. A positive diagnostic yield for all biopsies was 90.4%. The major and minor complication rates were 0% and 1.9% (1/52), respectively. Conclusion: Ultrasound-guided 18-G splenic biopsy is a safe and accurate procedure with no added risk of complications when compared with smaller needles or biopsy of other abdominal organs. Advances in knowledge: This is the largest case series of ultrasound-guided splenic biopsy with an 18-G needle, and our experience confirms a high diagnostic yield and a complication rate which compares favourably with the biopsy of other abdominal organs. PMID:26337505

  5. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... 1- to 2-Year-Old Aspiration and Biopsy: Bone Marrow KidsHealth > For Parents > Aspiration and Biopsy: Bone Marrow Print A A A What's in this article? ... Aspiraciones y biopsias: médula ósea What It Is Bone marrow aspirations and biopsies are performed to examine bone ...

  6. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... Your 1- to 2-Year-Old Aspiration and Biopsy: Bone Marrow KidsHealth > For Parents > Aspiration and Biopsy: Bone Marrow A A A What's in this ... ósea What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  7. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Aspiration and Biopsy: Bone Marrow KidsHealth > For Teens > Aspiration and Biopsy: Bone Marrow A A A What's in this ... Questions What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  8. Cost-effectiveness of two breast biopsy procedures: surgical biopsy versus vacuum-assisted biopsy.

    PubMed

    Pistolese, C A; Ciarrapico, A; Perretta, T; Cossu, E; della Gatta, F; Giura, S; Caramanica, C; Simonetti, G

    2012-06-01

    The aim of this study was to compare the cost-effectiveness of two breast biopsy procedures: surgical biopsy and vacuum-assisted biopsy (VAB). Between November 2008 and September 2009, 200 patients with suspicious breast lesions underwent biopsy procedures at our radiology department: 100 underwent VAB and 100 underwent surgical biopsy. 66 lesions were sampled under sonographic guidance, 109 under mammographic guidance and 25 under magnetic resonance guidance. All procedures were successfully completed. No significant differences in diagnostic efficacy were found between the biopsy procedures. Surgical biopsy has a higher unit cost compared with VAB. Our analysis emphasises the benefits of VAB compared with surgical biopsy in terms of both cost-effectiveness, and less invasiveness from a psychological and aesthetic point of view.

  9. Ultracoherent nanomechanical resonators via soft clamping and dissipation dilution.

    PubMed

    Tsaturyan, Y; Barg, A; Polzik, E S; Schliesser, A

    2017-08-01

    The small mass and high coherence of nanomechanical resonators render them the ultimate mechanical probe, with applications that range from protein mass spectrometry and magnetic resonance force microscopy to quantum optomechanics. A notorious challenge in these experiments is the thermomechanical noise related to the dissipation through internal or external loss channels. Here we introduce a novel approach to define the nanomechanical modes, which simultaneously provides a strong spatial confinement, full isolation from the substrate and dilution of the resonator material's intrinsic dissipation by five orders of magnitude. It is based on a phononic bandgap structure that localizes the mode but does not impose the boundary conditions of a rigid clamp. The reduced curvature in the highly tensioned silicon nitride resonator enables a mechanical Q > 10(8) at 1 MHz to yield the highest mechanical Qf products (>10(14) Hz) yet reported at room temperature.The corresponding coherence times approach those of optically trapped dielectric particles. Extrapolation to 4.2 K predicts quanta per milliseconds heating rates, similar to those of trapped ions.

  10. Transjugular Liver Biopsy: A Review of 77 Biopsies Using a Spring-Propelled Cutting Needle (Biopsy Gun)

    SciTech Connect

    Gorriz, Elias; Reyes, Ricardo; Lobrano, Mary Beth; Pulido-Duque, Juan M.; San Roman, Jose L.; Lonjedo, Elena; Ferral, Hector; Maynar, Manuel

    1996-11-15

    Seventy-seven transjugular liver biopsies were performed with a coaxial, spring-loaded, 18-gauge cutting needle, the Biopty gun (Bard Biopsy System, Covington, GA, USA) on consecutive patients between July 1993 and February 1995. Fifty men and 27 women were included in the study; the mean age was 45 years (range 15-69 years). The average number of punctures per patient was 5.2, with a range of 2-9, yielding an average of 4.8 samples per patient (range 1-7). The length of the samples varied from 10 to 22 mm with a constant diameter of 1 mm. The mean time required to complete the procedure was 48 min (43-52 min). Histological diagnoses were obtained in 74 of 77 patients (96%), with non-diagnostic specimens attributed to excessive fragmentation (3 cases). Complications occurred in 10 patients (puncture site hematoma, carotid artery puncture, abdominal pain, vasovagal reaction, hepatic capsule perforation, and hemobilia). The latter two complications were self-limited. In our experience this transjugular hepatic biopsy method is promising for performing biopsies in patients with chronic liver disease, due to its high success rate and low morbidity rate.

  11. Cell-Detection Technique for Automated Patch Clamping

    NASA Technical Reports Server (NTRS)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  12. Trends in Aortic Clamp Use During Coronary Artery Bypass Surgery: The Effect of Aortic Clamping Strategies on Neurologic Outcomes

    PubMed Central

    Daniel, William T.; Kilgo, Patrick; Puskas, John D.; Thourani, Vinod H.; Lattouf, Omar M.; Guyton, Robert A.; Halkos, Michael E.

    2013-01-01

    Objective The purpose of this study was to determine the impact of different clamping strategies during CABG on the incidence of postoperative stroke. Methods In this case-control study, all patients at Emory hospitals from 2002–2009 with postoperative stroke after isolated CABG (N=141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (N=565). Patients were matched according to the Society of Thoracic Surgeons (STS) Predicted Risk of Postoperative Stroke (PROPS), which is based on 26 variables. On- (ONCAB) and off-pump (OPCAB) patients were matched separately. Multiple logistic regression analysis with adjusted odds ratios (OR) was performed to identify operative variables associated with postoperative stroke. Results Among the ONCAB cohort, the single cross-clamp technique was associated with a decreased risk of stroke compared to the double clamp (cross clamp + partial clamp) technique (OR=0.385, p=0.044). Within the OPCAB cohort, there was no significant difference in stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002–2009, clamp use decreased from 97.7% of cases to 72.7%. Conclusions During ONCAB, the use of a single cross-clamp compared to the double clamp technique decreases the risk of postoperative stroke. The use of any aortic clamp has decreased and epiaortic ultrasound use has increased from 2002–2009, indicating a change in operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta. PMID:23477689

  13. Telepathology and Optical Biopsy

    PubMed Central

    Ferrer-Roca, Olga

    2009-01-01

    The ability to obtain information about the structure of tissue without taking a sample for pathology has opened the way for new diagnostic techniques. The present paper reviews all currently available techniques capable of producing an optical biopsy, with or without morphological images. Most of these techniques are carried out by physicians who are not specialized in pathology and therefore not trained to interpret the results as a pathologist would. In these cases, the use of telepathology or distant consultation techniques is essential. PMID:20339507

  14. Single electrode dynamic clamp with StdpC.

    PubMed

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-10-15

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations.

  15. Single electrode dynamic clamp with StdpC

    PubMed Central

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-01-01

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations. PMID:22898473

  16. Effect of delayed umbilical cord clamping on blood gas analysis.

    PubMed

    Valero, Javier; Desantes, Domingo; Perales-Puchalt, Alfredo; Rubio, Juan; Diago Almela, Vicente J; Perales, Alfredo

    2012-05-01

    To ascertain if there are differences in umbilical cord blood gas analysis between immediate and delayed cord clamping. In a prospective observational study on 60 vaginally delivered healthy term newborns, we sampled umbilical cord blood immediately after delivery and at the time umbilical cord pulsation spontaneously ceased. There were significant decreases in pH, oxygen saturation (sO(2)), glycemia, oxygen content (ctO(2)), bicarbonate (HCO(3)(-)) and base excess (BE). Lactate and [Formula: see text] increased. Delayed cord clamping pH correlated with immediate cord clamping pH, [Formula: see text] , ctHb, sO(2) and time (r(2)=0.77, p<0.000). Delayed cord clamping lactate was associated with immediate cord clamping lactate and time (r(2)=0.83, p<0.000). Delayed BE was associated with previous pH, lactate, glycemia, ctHb and time (r(2)=0.83, p<0.000). Delayed cord clamping alters acid-base parameters and lactate values compared to immediate cord clamping. Those variations depend mainly on time, prior pH and lactate. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  17. Committee Opinion No. 684: Delayed Umbilical Cord Clamping After Birth.

    PubMed

    2017-01-01

    Delayed umbilical cord clamping appears to be beneficial for term and preterm infants. In term infants, delayed umbilical cord clamping increases hemoglobin levels at birth and improves iron stores in the first several months of life, which may have a favorable effect on developmental outcomes. There is a small increase in jaundice that requires phototherapy in this group of infants. Consequently, health care providers adopting delayed umbilical cord clamping in term infants should ensure that mechanisms are in place to monitor for and treat neonatal jaundice. In preterm infants, delayed umbilical cord clamping is associated with significant neonatal benefits, including improved transitional circulation, better establishment of red blood cell volume, decreased need for blood transfusion, and lower incidence of necrotizing enterocolitis and intraventricular hemorrhage. Delayed umbilical cord clamping was not associated with an increased risk of postpartum hemorrhage or increased blood loss at delivery, nor was it associated with a difference in postpartum hemoglobin levels or the need for blood transfusion. Given the benefits to most newborns and concordant with other professional organizations, the American College of Obstetricians and Gynecologists now recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30-60 seconds after birth. The ability to provide delayed umbilical cord clamping may vary among institutions and settings; decisions in those circumstances are best made by the team caring for the mother-infant dyad.

  18. Single-Institution Results of Image-Guided Nonplugged Percutaneous Versus Transjugular Liver Biopsy

    SciTech Connect

    Hardman, Rulon L.; Perrich, Kiley D.; Silas, Anne M.

    2011-04-15

    Purpose: To retrospectively review patients who underwent transjugular and image-guided percutaneous biopsy and compare the relative risk of ascites, thrombocytopenia, and coagulopathy. Materials and Methods: From August 2001 through February 2006, a total of 238 liver biopsies were performed. The radiologist reviewed all patient referrals for transjugular biopsy. These patients either underwent transjugular biopsy or were reassigned to percutaneous biopsy (crossover group). Patients referred to percutaneous image-guided liver biopsy underwent this same procedure. Biopsies were considered successful if a tissue diagnosis could be made from the samples obtained. Results: A total of 36 transjugular biopsies were performed with 3 total (8.3%) and 1 major (2.8%) complications. A total of 171 percutaneous biopsies were performed with 10 (5.8%) total and 3 (1.8%) major complications. The crossover group showed a total of 4 (12.9%) complications with 1 (3.2%) major complication. Sample adequacy was 91.9% for transjugular and 99.5% for percutaneous biopsy. Conclusion: Both transjugular and percutaneous liver biopsy techniques are efficacious and safe. Contraindications such as thrombocytopenia, coagulopathy, and ascites are indicators of greater complications but are not necessarily prevented by transjugular biopsy. Percutaneous biopsy more frequently yields a diagnostic specimen than transjugular biopsy.

  19. Avoiding aortic clamping during CABG reduces postoperative stroke

    PubMed Central

    Moss, Emmanuel; Puskas, John D; Thourani, Vinod H; Kilgo, Patrick; Chen, Edward P; Leshnower, Bradley G; Lattouf, Omar M; Guyton, Robert A.; Glas, Kathryn E; Halkos, Michael E.

    2014-01-01

    Objective The purpose of this study was to determine whether the incidence of postoperative stroke (PS) could be reduced by eliminating aortic clamping during CABG. Methods From 2002–2013, 12,079 patients underwent primary, isolated CABG at a single US academic institution. Aortic manipulation was completely avoided by using in-situ internal mammary arteries for inflow in 1,552 (12.9%) patients (no-touch), a clampless facilitating device (CFD) was used for proximal anastomoses in 1,548 (12.8%) patients, and aortic clamping was used in 8,979 (74.3%) patients. These strategies were assessed in a logistic regression model controlling for relevant variables. Results The overall incidence of PS was 1.4% (n=165), with an unadjusted incidence of 0.6% (n=10) in the no-touch group, 1.2% (n=18) in the CFD group, and 1.5% (n=137) in the clamp group (p<0.01 for no-touch vs clamp). The ratio of observed to expected stroke rate increased as the degree of aortic manipulation increased, from 0.48 in the no-touch group, to 0.61 in the CFD group, and 0.95 in the clamp group. Aortic clamping was independently associated with an increase in PS compared to a no-touch technique (AOR 2.50, p<0.01). When separated by CPB utilization, both the off-pump partial clamp and on-pump cross-clamp techniques increased the risk of PS compared to no-touch (AOR 2.52, p<0.01 and AOR 4.25, p<0.001, respectively). Conclusion A no-aortic touch technique has the lowest risk for postoperative stroke for patients undergoing CABG. Clamping the aorta during CABG increases the risk of PS, regardless of the severity of aortic disease. PMID:25293356

  20. Reciprocating clamp apparatus for thermoforming plastic containers

    SciTech Connect

    Beck, M.H.; Harry, I.L.; Krishnakumar, S.M.

    1984-03-06

    This relates to the forming of containers and like hollow articles from sheets or webs of thermoplastic material. Two webs or sheets are simultaneously acted upon by way of a forming apparatus which includes a reciprocating clamp first cooperable with one outer platen and then the other in sequence wherein, while a first web or sheet is being formed within a plurality of mold cavities to define a plurality of hollow articles such as containers, the other sheet or web may be stripped from its respective mold set and a new sheet or a new portion of a sheet or web may be advanced into position for molding. The forming apparatus may be constructed in a manner wherein the web portions which are to be formed may be billowed away from the mold cavities as an initial step in the stretching and orientation of the thermoplastic material. The thermoplastic material may be heated to the desired forming temperature using separate sets of rf electrodes so that only those portions of the thermoplastic material which are to be formed need be heated. Two sets of containers of different sizes may be formed from the webs or sheets, and then internested to form double wall containers wherein the walls may be formed of different materials and wherein the outer material may be a barrier material, or wherein the walls of the containers are spaced apart to form an insulated container. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

  1. The clinical significance of lobular neoplasia on breast core biopsy.

    PubMed

    Karabakhtsian, Rouzan G; Johnson, Ronald; Sumkin, Jules; Dabbs, David J

    2007-05-01

    A core biopsy diagnosis of atypical ductal epithelial hyperplasia is upstaged on follow-up excisional biopsy (FUEB) to in situ or invasive carcinoma in about 20% of cases, thus prompting a FUEB. In contrast, upstaging information for a core biopsy diagnosis of pure lobular neoplasia (LN), without mass lesions or other risk-associated lesions is less clear. In this retrospective study, we report the largest consecutive series of patients who had a breast core biopsy diagnosis of LN and a FUEB. Core needle breast biopsies with a diagnosis of LN were retrieved from our files for the period 1999 to 2005, yielding 110 patients. One hundred and one patients had a follow-up surgical excision. Cases of LN with coexisting high-risk lesions (n=9, 10%) were excluded from the study. Patients with associated mass lesions all had benign findings (n=15, 16%) and had no impact on the study results. The remaining 77 core biopsies had no masses or risk lesions and were mammographically Breast Imaging Reporting and Data System 4 (BIRADS) for microcalcifications. Overall, 8/77 (10%) of patients with a radiographic BIRADS 4 image with calcifications and a core biopsy diagnosis of LN on core biopsy were upstaged on FUEB to ductal carcinoma in situ or invasive carcinoma. The numbers upstaged from core biopsies were as follows: atypical lobular hyperplasia (ALH) 4/52 (8%), mixed ALH/lobular carcinoma in situ (LCIS) 1/9 (10%), and pure LCIS 3/16 (19%). A core biopsy of LCIS with neoplastic epithelial calcifications was nearly 3 times more likely to be upstaged on FUEB compared with ALH. We conclude that a finding of LN on breast core biopsy in a patient with a BIRADS 4 image and calcifications is associated with a risk of 8% to 19% of upstaging to a treatable disease on FUEB.

  2. Percutaneous transbiliary biopsy.

    PubMed

    Andrade, Gustavo Vieira; Santos, Miguel Arcanjo; Meira, Marconi Roberto; Meira, Mateus Duarte

    2017-01-01

    Percutaneous drainage of the bile ducts is an established procedure for malignant obstructions, in which a histological diagnosis is often not obtained. We describe the biopsy technique of obstructive lesions through biliary drainage access, using a 7F endoscopic biopsy forceps, widely available; some are even reusable. This technique applies to lesions of the hepatic ducts, of the common hepatic duct and of all extension of the common bile duct. RESUMO A drenagem percutânea das vias biliares é um procedimento estabelecido para obstruções malignas, nos quais, muitas vezes, não se consegue um diagnóstico histológico. Descrevemos a técnica de biópsia da lesão obstrutiva através do acesso de drenagem biliar, utilizando um fórcipe de biópsia endoscópica 7F, amplamente disponível e alguns reutilizáveis. Esta técnica aplica-se a lesões dos ductos hepáticos, do hepático comum e de toda extensão do colédoco.

  3. Diffuse reflectance imaging: a tool for guided biopsy

    NASA Astrophysics Data System (ADS)

    Jayanthi, Jayaraj L.; Subhash, Narayanan; Manju, Stephen; Nisha, Unni G.; Beena, Valappil T.

    2012-01-01

    Accurate diagnosis of premalignant or malignant oral lesions depends on the quality of the biopsy, adequate clinical information and correct interpretation of the biopsy results. The major clinical challenge is to precisely locate the biopsy site in a clinically suspicious lesion. Dips due to oxygenated hemoglobin absorption have been noticed at 545 and 575 nm in the diffusely reflected white light spectra of oral mucosa and the intensity ratio R545/R575 has been found suited for early detection of oral pre-cancers. A multi-spectral diffuse reflectance (DR) imaging system has been developed consisting of an electron multiplying charge coupled device (EMCCD) camera and a liquid crystal tunable filter for guiding the clinician to an optimal biopsy site. Towards this DR images were recorded from 27 patients with potentially malignant lesions on their tongue (dorsal, lateral and ventral sides) and from 44 healthy controls at 545 and 575 nm with the DR imaging system. False colored ratio image R545/R575 of the lesion provides a visual discerning capability that helps in locating the most malignant site for biopsy. Histopathological report of guided biopsy showed that out of the 27 patients 16 were cancers, 9 pre-cancers and 2 lichen planus. In this clinical trial DR imaging has correctly guided 25 biopsy sites, yielding a sensitivity of 93% and a specificity of 98%, thereby establishing the potential of DR imaging as a tool for guided biopsy.

  4. Induction of DNA DSB and its rejoining in clamped and non-clamped tumours after exposure to carbon ion beams in comparison to X rays.

    PubMed

    Hirayama, R; Uzawa, A; Matsumoto, Y; Noguchi, M; Kase, Y; Takase, N; Ito, A; Koike, S; Ando, K; Okayasu, R; Furusawa, Y

    2011-02-01

    We studied double-strand breaks (DSB) induction and rejoining in clamped and non-clamped transplanted tumours in mice leg after exposure to 80 keV µm(-1) carbon ions and X rays. The yields of DSB in the tumours were analysed by a static-field gel electrophoresis. The OER of DSB after X rays was 1.68±0.31, and this value was not changed after 1 h rejoining time (1.40±0.26). These damages in oxygenated conditions were rejoined 60-70% within 1 h in situ. No difference was found between the exposure to X rays and carbon ions for the induction and rejoining of DSB. Thus, the values of OER and rejoined fraction after exposure to carbon ions were similar to those after X rays, and the calculated relative biological effectivenesses of carbon ion were around 1 under both oxygen conditions. The yields of DSB in vivo depend on exposure doses, oxygen conditions and rejoining time, but not on the types of radiation quality.

  5. Ultrasound-guided synovial Tru-cut biopsy: indications, technique, and outcome in 111 cases.

    PubMed

    Sitt, Jacqueline C M; Griffith, James F; Lai, Fernand M; Hui, Mamie; Chiu, K H; Lee, Ryan K L; Ng, Alex W H; Leung, Jason

    2017-05-01

    To investigate the diagnostic performance of ultrasound-guided synovial biopsy. Clinical notes, pathology and microbiology reports, ultrasound and other imaging studies of 100 patients who underwent 111 ultrasound-guided synovial biopsies were reviewed. Biopsies were compared with the final clinical diagnosis established after synovectomy (n = 43) or clinical/imaging follow-up (n = 57) (mean 30 months). Other than a single vasovagal episode, no complication of synovial biopsy was encountered. One hundred and seven (96 %) of the 111 biopsies yielded synovium histologically. Pathology ± microbiology findings for these 107 conclusive biopsies comprised synovial tumour (n = 30, 28 %), synovial infection (n = 18, 17 %), synovial inflammation (n = 45, 42 %), including gouty arthritis (n = 3), and no abnormality (n = 14, 13 %). The accuracy, sensitivity, and specificity of synovial biopsy was 99 %, 97 %, and 100 % for synovial tumour; 100 %, 100 %, and 100 % for native joint infection; and 78 %, 45 %, and 100 % for prosthetic joint infection. False-negative synovial biopsy did not seem to be related to antibiotic therapy. Ultrasound-guided Tru-cut synovial biopsy is a safe and reliable technique with a high diagnostic yield for diagnosing synovial tumour and also, most likely, for joint infection. Regarding joint infection, synovial biopsy of native joints seems to have a higher diagnostic yield than that for infected prosthetic joints. • Ultrasound-guided Tru-cut synovial biopsy has high accuracy (99 %) for diagnosing synovial tumour. • It has good accuracy, sensitivity, and high specificity for diagnosis of joint infection. • Synovial biopsy of native joints works better than biopsy of prosthetic joints. • A negative synovial biopsy culture from a native joint largely excludes septic arthritis. • Ultrasound-guided Tru-cut synovial biopsy is a safe and well-tolerated procedure.

  6. The Application of Mechanical Clamps to Portsmouth Connectors.

    DTIC Science & Technology

    1981-11-23

    Resistance Readings ..... .............. .64 TABLE 12 - ALT SUMM!ARY - POLYURETHANE CONNECTORS Resis- ance Readings ..... .............. .65 v7 ft...34 FIGURE 17 Pressure Tank Pressure Fittings . ........ . 37 vi I THE APPLICATION OF MECHANICAL CLAMPS TO PORTSMOUTH CONNECTORS BACKGROUN )D This

  7. Studying mechanosensitive ion channels with an automated patch clamp.

    PubMed

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Koçer, Armağan

    2014-03-01

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they could not be applied to MSCs. Here, we report on activation and single channel analysis of a bacterial mechanosensitive ion channel using an automated patch clamp system. With the automated system, we could patch not only giant unilamellar liposomes but also giant Escherichia coli (E. coli) spheroplasts. The tension sensitivity and channel kinetics data obtained in the automated system were in good agreement with that obtained from the conventional patch clamp. The findings will pave the way to high throughput fundamental and drug screening studies on mechanosensitive ion channels.

  8. A clamp-like biohybrid catalyst for DNA oxidation

    NASA Astrophysics Data System (ADS)

    van Dongen, Stijn F. M.; Clerx, Joost; Nørgaard, Kasper; Bloemberg, Tom G.; Cornelissen, Jeroen J. L. M.; Trakselis, Michael A.; Nelson, Scott W.; Benkovic, Stephen J.; Rowan, Alan E.; Nolte, Roeland J. M.

    2013-11-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a processivity mediator by encircling DNA and subsequently recruiting its polymerase. Here we use this DNA-binding protein to construct a biohybrid catalyst. Conjugation of the clamp protein to a chemical catalyst with sequence-specific oxidation behaviour formed a catalytic clamp that can be loaded onto a DNA plasmid. The catalytic activity of the biohybrid catalyst was visualized using a procedure based on an atomic force microscopy method that detects and spatially locates oxidized sites in DNA. Varying the experimental conditions enabled switching between processive and distributive catalysis and influencing the sliding direction of this rotaxane-like catalyst.

  9. Value of Targeted Prostate Biopsy Using Magnetic Resonance–Ultrasound Fusion in Men with Prior Negative Biopsy and Elevated Prostate-specific Antigen

    PubMed Central

    Sonn, Geoffrey A.; Chang, Edward; Natarajan, Shyam; Margolis, Daniel J.; Macairan, Malu; Lieu, Patricia; Huang, Jiaoti; Dorey, Frederick J.; Reiter, Robert E.; Marks, Leonard S.

    2013-01-01

    Background Conventional biopsy fails to detect the presence of some prostate cancers (PCas). Men with a prior negative biopsy but persistently elevated prostate-specific antigen (PSA) pose a diagnostic dilemma, as some harbor elusive cancer. Objective To determine whether use of magnetic resonance–ultrasound (MR-US) fusion biopsy results in improved detection of PCa compared to repeat conventional biopsy. Design, setting, and participants In a consecutive-case series, 105 subjects with prior negative biopsy and elevated PSA values underwent multiparametric magnetic resonance imaging (MRI) and fusion biopsy in an outpatient setting. Intervention Suspicious areas on multiparametric MRI were delineated and graded by a radiologist; MR–US fusion biopsy was performed by a urologist using the Artemis device; targeted and systematic biopsies were obtained regardless of MRI result. Outcome measurements and statistical analysis Detection rates of all PCa and clinically significant PCa (Gleason ≥3 + 4 or Gleason 6 with maximal cancer core length ≥4 mm) were determined. The yield of targeted biopsy was compared to systematic biopsy. The ability of an MRI grading system to predict clinically significant cancer was investigated. Stepwise multivariate logistic regression analysis was performed to determine predictors of significant cancer on biopsy. Results and limitations Fusion biopsy revealed PCa in 36 of 105 men (34%; 95% confidence interval [CI], 25–45). Seventy-two percent of men with PCa had clinically significant disease; 21 of 23 men (91%) with PCa on targeted biopsy had significant cancer compared to 15 of 28 (54%) with systematic biopsy. Degree of suspicion on MRI was the most powerful predictor of significant cancer on multivariate analysis. Twelve of 14 (86%) subjects with a highly suspicious MRI target were diagnosed with clinically significant cancer. Conclusions MR-US fusion biopsy provides improved detection of PCa in men with prior negative biopsies

  10. Molecular jamming--the cystine slipknot mechanical clamp in all-atom simulations.

    PubMed

    Pepłowski, Lukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-28

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids.

  11. Molecular jamming—The cystine slipknot mechanical clamp in all-atom simulations

    NASA Astrophysics Data System (ADS)

    Pepłowski, Łukasz; Sikora, Mateusz; Nowak, Wiesław; Cieplak, Marek

    2011-02-01

    A recent survey of 17 134 proteins has identified a new class of proteins which are expected to yield stretching induced force peaks in the range of 1 nN. Such high force peaks should be due to forcing of a slip-loop through a cystine ring, i.e., by generating a cystine slipknot. The survey has been performed in a simple coarse grained model. Here, we perform all-atom steered molecular dynamics simulations on 15 cystine knot proteins and determine their resistance to stretching. In agreement with previous studies within a coarse grained structure based model, the level of resistance is found to be substantially higher than in proteins in which the mechanical clamp operates through shear. The large stretching forces arise through formation of the cystine slipknot mechanical clamp and the resulting steric jamming. We elucidate the workings of such a clamp in an atomic detail. We also study the behavior of five top strength proteins with the shear-based mechanostability in which no jamming is involved. We show that in the atomic model, the jamming state is relieved by moving one amino acid at a time and there is a choice in the selection of the amino acid that advances the first. In contrast, the coarse grained model also allows for a simultaneous passage of two amino acids.

  12. Robotic multi-well planar patch-clamp for native and primary mammalian cells

    PubMed Central

    Milligan, Carol J; Li, Jing; Sukumar, Piruthivi; Majeed, Yasser; Dallas, Mark L; English, Anne; Emery, Paul; Porter, Karen E; Smith, Andrew M; McFadzean, Ian; Beccano-Kelly, Dayne; Bahnasi, Yahya; Cheong, Alex; Naylor, Jacqueline; Zeng, Fanning; Liu, Xing; Gamper, Nikita; Jiang, Lin-Hua; Pearson, Hugh A; Peers, Chris; Robertson, Brian; Beech, David J

    2009-01-01

    Multi-well robotic planar patch-clamp has become common in drug development and safety programmes because it enables efficient and systematic testing of compounds against ion channels during voltage-clamp. It has not, however, been adopted significantly in other important areas of ion channel research, where conventional patch-clamp remains the favoured method. Here we show the wider potential of the multi-well approach with the capability for efficient intracellular solution exchange, describing protocols and success rates for recording from a range of native and primary mammalian cells derived from blood vessels, arthritic joints, and the immune and central nervous systems. The protocol involves preparing a suspension of single cells to be dispensed robotically into 4-8 microfluidic chambers each containing a glass chip with a small aperture. Under automated control, giga-seals and whole-cell access are achieved followed by pre-programmed routines of voltage paradigms and fast extracellular or intracellular solution exchange. Recording from 48 chambers usually takes 1-6 hr depending on the experimental design and yields 16-33 cell recordings. PMID:19197268

  13. Spatial dynamics, thermalization, and gain clamping in a photon condensate

    NASA Astrophysics Data System (ADS)

    Keeling, Jonathan; Kirton, Peter

    2016-01-01

    We study theoretically the effects of pump-spot size and location on photon condensates. By exploring the inhomogeneous molecular excitation fraction, we make clear the relation between spatial equilibration, gain clamping, and thermalization in a photon condensate. This provides a simple understanding of several recent experimental results. We find that as thermalization breaks down, gain clamping is imperfect, leading to "transverse spatial hole burning" and multimode condensation. This opens the possibility of engineering the gain profile to control the condensate structure.

  14. Lotus birth, a holistic approach on physiological cord clamping.

    PubMed

    Zinsser, Laura A

    2017-09-04

    The positive effects of delayed cord clamping (DCC) has been extensively researched. DCC means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. With physiological clamping and cutting (PCC) the clamping and cutting can happen at the earliest after the pulsation has stopped. With a Lotus birth, no clamping and cutting of the cord is done. A woman called Clair Lotus Day imitated the holistic approach of PCC from an anthropoid ape in 1974. The chimpanzee did not separate the placenta from the newborn. The aim of this case report is to discuss and learn a different approach in the third stage of labour. Three cases of Lotus birth by human beings were observed. All three women gave birth in an out-of-hospital setting and had ambulant postnatal care. The placenta was washed, salted and herbs were put on 2-3h post partum. The placenta was wrapped in something that absorbs the moisture. The salting was repeated with a degreasing frequency depending on moistness of the placenta. On life day six all three Lotus babies experiences a natural separation of the cord. All three Lotus birth cases were unproblematic, no special incidence occurred. One should differentiate between early cord clamping (ECC), delayed cord clamping (DCC) and physiological cord clamping (PCC). Lotus birth might lead to an optimisation of the bonding and attachment. Research is needed in the areas of both PCC and Lotus birth. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  15. LIVER BIOPSY IN HUMAN LEPTOSPIROSIS.

    DTIC Science & Technology

    LEPTOSPIRA, DISEASES), (*LIVER, BIOPSY), LEPTOSPIRA ICTEROHAEMORRHAGIAE, HUMANS, PATHOLOGY, CELL STRUCTURE, MITOCHONDRIA, NECROSIS, ENZYMES, TOXINS AND ANTITOXINS, KIDNEYS, PARASITES, ELECTRON MICROSCOPY, BRAZIL

  16. Evaluation of biopsy methods in the diagnosis of submandibular space pathology.

    PubMed

    Olubaniyi, B O; Chow, V; Mandalia, U; Haldar, S; Gok, G; Michl, P; Ramesar, K; Sellon, E; Williams, M; Howlett, D C

    2014-03-01

    The aim of this study was to evaluate the performance of fine needle aspiration cytology (FNAC), ultrasound-guided core needle biopsy (USCNB), punch biopsy, and surgical excision biopsy in neoplasms presenting within the submandibular space. A retrospective analysis of all patients with a pathological diagnosis of a submandibular space neoplasm within a 12-year period (February 1999 to June 2011) was performed. Biopsy results were compared to histopathological diagnosis obtained from surgical excision biopsy. Eighty-one specimens from 44 patients met the search criteria (15 FNAC, 24 USCNB, 7 punch biopsy, and 35 surgical excision biopsy). The final diagnosis was established by USCNB, punch biopsy, or surgical excision biopsy and not by FNAC alone. Surgical excision biopsy was performed as a primary diagnostic (n = 8), secondary diagnostic (n = 15), or as a post-diagnostic therapeutic procedure (n = 12). Non-diagnostic results were: FNAC 11/15, USCNB 2/24, and punch biopsy 1/7. Diagnostic results were: FNAC 2/15, USCNB 20/24, and punch biopsy 5/7. No complications were reported. Although punch biopsy demonstrated good yield and accuracy, its use is restricted to a small cohort of patients. USCNB is a safe and accurate technique in the submandibular space, with a low non-diagnostic rate.

  17. Negative Biopsy after Referral for Biopsy-Proven Gastric Cancer

    PubMed Central

    Tae, Chung Hyun; Lee, Jun Haeng; Min, Byung-Hoon; Kim, Kyoung-Mee; Rhee, Poong-Lyul; Kim, Jae J.

    2016-01-01

    Background/Aims Repeat endoscopy with biopsy is often performed in patients with previously diagnosed gastric cancer to determine further treatment plans. However, biopsy results may differ from the original pathologic report. We reviewed patients who had a negative biopsy after referral for gastric cancer. Methods A total of 116 patients with negative biopsy results after referral for biopsy-proven gastric cancer were enrolled. Outside pathology slides were reviewed. Images of the first and second endoscopic examinations were reviewed. We reviewed the clinical history from referral to the final treatment. Results Eighty-eight patients (76%) arrived with information about the lesion from the referring physician. Among 96 patients with available outside slides, the rate of interobserver variation was 24%. Endoscopy was repeated at our institution; 85 patients (73%) were found to have definite lesions, whereas 31 patients (27%) had indeterminate lesions. In the group with definite lesions, 71% of the lesions were depressed in shape. The most common cause of a negative biopsy was mistargeting. In the group with indeterminate lesions, 94% had insufficient information. All patients with adequate follow-up were successfully treated based on the findings in the follow-up endoscopy. Conclusions A negative biopsy after referral for biopsy-proven gastric cancer is mainly caused by mistargeting and insufficient information during the referral. PMID:25963084

  18. Optimized technique in needle biopsy protocol shown to be of greater sensitivity and accuracy compared to wedge biopsy.

    PubMed

    Yushkov, Y; Dikman, S; Alvarez-Casas, J; Giudice, A; Hoffman, A; Goldstein, M J

    2010-09-01

    Kidney biopsy is an important tool in determining allograft suitability for transplantation. Most deceased-donor renal biopsies performed today in the United States are wedge biopsies (WBs), with core needle biopsies being performed only by a minority of organ procurement organizations (OPOs). The lack of a gold standard in tissue sampling and tissue evaluation has prompted our OPO to find a more sensitive biopsy method as well as a more accurate pathology evaluation protocol to reassess expanded-criteria donor kidneys. Between the months of March 2007 and June 2008, the New York Organ Donor Network OPO imported 226 kidneys. These kidneys had been previously biopsied by the originating OPOs utilizing the WB method. All 226 kidneys were rebiopsied by our preservation team using the optimized needle biopsy technique (ONBT) and then evaluated by the pathologists of the Transplant Pathology Laboratory of the Mount Sinai Hospital. Histologic findings from both types of biopsies were compared in the following parameters: glomerular yield, percentage of obsolete glomeruli, tubular interstitial scarring, arterial intimal fibrosis and acute tubular necrosis. Difference in glomerular yield between WB and ONBT was not statistically significant (P = .1736). ONBT detected more tubular interstitial scarring and arterial intimal fibrous narrowing than WB (P = .00). No statistical difference was found between the two biopsy methods in identifying acute tubular necrosis. The data suggest that there were no statistical differences in sample reliability between ONBT and WB. However, ONBT was found to be significantly more sensitive in identifying allograft tubular interstitial scarring as well as intimal fibrous narrowing. Overall this study provides proof that ONBT is a more reliable and accurate method compared to WB in identifying important parameters of renal allograft. 2010 Elsevier Inc. All rights reserved.

  19. Ventilation Onset Prior to Umbilical Cord Clamping (Physiological-Based Cord Clamping) Improves Systemic and Cerebral Oxygenation in Preterm Lambs

    PubMed Central

    Polglase, Graeme R.; Dawson, Jennifer A.; Kluckow, Martin; Gill, Andrew W.; Davis, Peter G.; te Pas, Arjan B.; Crossley, Kelly J.; McDougall, Annie; Wallace, Euan M.; Hooper, Stuart B.

    2015-01-01

    Background As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. Aim We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Methods Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Results Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5–6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. Conclusion The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room. PMID:25689406

  20. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    PubMed

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  1. Nonlinear response of a clamped-clamped beam with internal resonance under sinusoidal excitation

    NASA Astrophysics Data System (ADS)

    Afaneh, Abdul-Hafiz Ahmed

    1992-01-01

    The nonlinear response characteristics of a clamped-clamped beam is investigated analytically, numerically, and experimentally. The beam is under an initial static axial load and subjected to a harmonic excitation of its support. Two ranges of the axial load are considered. These are below (the beam is initially straight) and above Euler buckling load (the beam is initially buckled). Hamilton's principle is used to derive a fourth order partial differential equation of motion which is descritized and reduced to a set of second order ordinary differential equations by applying Galerkin's method. Under certain values of the static load, the normal modes are nonlinearly coupled and this coupling results in a fourth order internal resonance condition between the first three modes when the beam is initially straight. Second and third order internal resonance conditions occur between the first two modes for the case of initially buckled beam. The multiple scales method showed the significant effects of these internal resonance conditions on the system behavior. In the straight beam case, the third mode which is externally excited transfers energy to the first two modes within a small range of internal detuning. Outside this region, the response is governed by a unimodal response of the third mode. In the neighborhood of 1:1 internal resonance, it is found that within the region of two mode interaction, the solution is either stationary or nonstationary depending on the excitation level and system parameters. Saturation and jump phenomena are found to take place in the case of two mode interaction with 2:1 internal resonance. Numerical simulation and experimental testing confirmed these predictions and revealed the occurrence of multifurcation, snap-through (escaping from one well to the other in an irregular manner), and chaotic motion.

  2. Pediatric renal transplant biopsy with ultrasound guidance: the 'core' essentials.

    PubMed

    Oates, Aris; Ahuja, Saveen; Lee, Marsha M; Phelps, Andrew S; Mackenzie, John D; Courtier, Jesse L

    2017-06-01

    This review provides a comprehensive and practical approach to pediatric percutaneous renal transplant biopsies, highlighting techniques and strategies to optimize adequate sample yield and ensure patient safety. In children with end-stage renal disease, transplantation is the preferred choice of therapy, providing for overall lower long-term morbidity and mortality compared with dialysis. In the ongoing management of renal transplant patients, core tissue sampling via a percutaneous renal biopsy remains the gold standard when transplant dysfunction is suspected. Indications for renal transplant biopsy and techniques/tools for adequate sample yield are discussed. Strategies for common challenges such as poor visualization and renal transplant mobility are addressed. We discuss the clinical signs, techniques and imaging findings for common complications including hematomas, arteriovenous fistulas and pseudoaneurysms. Although the percutaneous renal transplant biopsy procedure is generally safe with rare complications, care must be taken to ensure major complications are promptly recognized and treated. Adequate tissue samples obtained via renal biopsy are imperative to promptly identify transplant rejection to provide valuable information for patient diagnosis, treatment and outcomes. Radiologist and nephrologist attention to proper ultrasound techniques and optimal biopsy tools are critical to ensure tissue adequacy and minimize complications.

  3. ATP binding and hydrolysis-driven rate-determining events in the RFC-catalyzed PCNA clamp loading reaction.

    PubMed

    Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2012-02-17

    The multi-subunit replication factor C (RFC) complex loads circular proliferating cell nuclear antigen (PCNA) clamps onto DNA where they serve as mobile tethers for polymerases and coordinate the functions of many other DNA metabolic proteins. The clamp loading reaction is complex, involving multiple components (RFC, PCNA, DNA, and ATP) and events (minimally: PCNA opening/closing, DNA binding/release, and ATP binding/hydrolysis) that yield a topologically linked clamp·DNA product in less than a second. Here, we report pre-steady-state measurements of several steps in the reaction catalyzed by Saccharomyces cerevisiae RFC and present a comprehensive kinetic model based on global analysis of the data. Highlights of the reaction mechanism are that ATP binding to RFC initiates slow activation of the clamp loader, enabling it to open PCNA (at ~2 s(-1)) and bind primer-template DNA (ptDNA). Rapid binding of ptDNA leads to formation of the RFC·ATP·PCNA(open)·ptDNA complex, which catalyzes a burst of ATP hydrolysis. Another slow step in the reaction follows ATP hydrolysis and is associated with PCNA closure around ptDNA (8 s(-1)). Dissociation of PCNA·ptDNA from RFC leads to catalytic turnover. We propose that these early and late rate-determining events are intramolecular conformational changes in RFC and PCNA that control clamp opening and closure, and that ATP binding and hydrolysis switch RFC between conformations with high and low affinities, respectively, for open PCNA and ptDNA, and thus bookend the clamp loading reaction.

  4. Ultrasound-guided chest biopsies.

    PubMed

    Middleton, William D; Teefey, Sharlene A; Dahiya, Nirvikar

    2006-12-01

    Pulmonary nodules that are surrounded by aerated lung cannot be visualized with sonography. Therefore, percutaneous biopsy must be guided with computed tomography or fluoroscopy. Although this restriction only applies to central lung nodules, it has permeated referral patterns for other thoracic lesions and has retarded the growth of ultrasound-guided interventions. Nevertheless, sonography is an extremely flexible modality that can expeditiously guide many biopsy procedures in the thorax. Peripheral pulmonary nodules can be successfully biopsied with success rates exceeding 90% and complications rates of less than 5%. Orienting the probe parallel to the intercostal space facilitates biopsies of peripheral pulmonary nodules. Anterior mediastinal masses that extend to the parasternal region are often easily approachable provided the internal mammary vessels, costal cartilage, and deep great vessels are identified and avoided. Superior mediastinal masses can be sampled from a suprasternal or supraclavicular approach. Phased array probes or tightly curved arrays may provide improved access for biopsies in this location. Posterior mediastinal masses are more difficult to biopsy with ultrasound guidance because of the overlying paraspinal muscles. However, when posterior mediastinal masses extend into the posterior medial pleural region, they can be biopsied with ultrasound guidance. Because many lung cancers metastasize to the supraclavicular nodes, it is important to evaluate the supraclavicular region when determining the best approach to obtain a tissue diagnosis. When abnormal supraclavicular nodes are present, they often are the easiest and safest lesions to biopsy.

  5. Oral biopsy in dental practice.

    PubMed

    Mota-Ramírez, Amparo; Silvestre, Francisco Javier; Simó, Juan Manuel

    2007-11-01

    The conclusions drawn from the study of an oral biopsy are considered essential for the definitive diagnosis of diseases of the oral mucosa, and for the subsequent planning of appropriate treatment. Although the obtainment of biopsies is widely used in all medical fields, the practice is not so widespread in dental practice--fundamentally because of a lack of awareness of the procedure among dental professionals. In this context, it must be taken into account that the early diagnosis of invasive oral malignancy may be critical for improving the patient prognosis. However, in some cases the results are adversely affected by incorrect manipulation of the biopsy material. The present study provides an update on the different biopsy sampling techniques and their application. Such familiarization in turn will contribute to knowledge of the material and instruments required for correct biopsy performance in dentistry, as well as of the material required for correct sample storage and transport.

  6. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  7. Spectral infrared hemispherical reflectance measurements for LDEF tray clamps

    NASA Technical Reports Server (NTRS)

    Wood, Bobby E.; Cromwell, Brian K.; Pender, Charles W.; Shepherd, Seth D.

    1992-01-01

    This paper describes infrared hemispherical reflectance measurements (2-15 microns) that were made on 58 chromic acid anodized tray clamps retrieved from the LDEF spacecraft. These clamps were used for maintaining the experiments in place and were located at various locations about the spacecraft. Changes in reflectance of the tray clamps at these locations were compared with atomic oxygen fluxes at the same locations. A decrease in absorption band depth was seen for the surfaces exposed to space indicating that there was some surface layer erosion. In all of the surfaces measured, little evidence of contamination was observed and none of the samples showed evidence of the brown nicotine stain that was so prominent in other experiments. Total emissivity values were calculated for both exposed and unexposed tray clamp surfaces. Only small differences, usually less than 1 percent, were observed. The spectral reflectances were measured using a hemi-ellipsoidal mirror reflectometer matched with an interferometer spectrometer. The rapid scanning capability of the interferometer allowed the reflectance measurements to be made in a timely fashion. The ellipsoidal mirror has its two foci separated by 2 inches and located on the major axis. A blackbody source was located at one focus while the tray clamp samples were located at the conjugate focus. The blackbody radiation was modulated and then focused by the ellipsoid onto the tray clamps. Radiation reflected from the tray clamp was sampled by the interferometer by viewing through a hole in the ellipsoid. A gold mirror (reflectance approximately 98 percent) was used as the reference surface.

  8. [Comparison of hot versus cold biopsy forceps in the diagnosis of endobronchial lesions].

    PubMed

    Firoozbakhsh, Shahram; Seifirad, Soroush; Safavi, Enayat; Dinparast, Reza; Taslimi, Shervin; Derakhshandeilami, Gholamreza

    2011-11-01

    Traditionally cold biopsy forceps were used for endobronchial biopsy, and recently electrocautery (hot) bronchoscopy biopsy forceps are introduced. It is hypothesized that hot biopsy forceps may decrease procedure related bleeding and also may decrease the quality of obtained samples. Patients with different indications for endobronchial biopsy during fiberoptic bronchoscopy underwent three hot and three cold biopsies with a random fashion. All biopsies were obtained with a single biopsy forceps with and without the application of an electrocoagulation current, set on soft coagulation mode (40W). A four point scale was used for quantification of bleeding. A single pathologist blinded to the patients' history was requested to review all samples. A three point scale was used to assess electrocoagulation damage. A total of 240 biopsies were obtained from 40 patients. Frequency of positive concordance between the two methods was 85%. The degree of electrocoagulation damage of the samples was as follows: grade 1=52.5%, grade 2=32.5%, and grade 3=15%. The average bleeding score following hot biopsy was significantly lower compared to the cold biopsy (P=.006). The concordance between diagnostic yield of hot and cold biopsies was 85%. There was no significant difference between the diagnostic yields of two biopsy methods (P=.687). Hot biopsy forceps significantly decreased the procedure related bleeding. The quality of samples was not impaired significantly. Regarding low prevalence of bleeding following endobronchial biopsy, routine use of hot bronchoscopy forceps is not reasonable. However, familiarity of bronchoscopists with this method may improve bronchoscopy safety. Copyright © 2011 SEPAR. Published by Elsevier Espana. All rights reserved.

  9. [Surgical pleural biopsy].

    PubMed

    Bracco, A N; Bouteiller, J M; Della Torre, H A; Golonbek, M

    1965-10-01

    The authors emphasize on the importance of histologic study of the sick pleura to obtain a diagnosis and to decide the treatment, operative or not, which must be specific. They choose the surgical biopsy and analyze the results obtained in 104 operations performed on 100 patients. Four groups of lesions are established: 1) malignant tumors (primary and secondary), 2) Non specific pleuritis consecutive to carcinoma of the lung or other organs, usually metastatic from the breast or the digestive tract, 3) Non specific pleuritis, and 4) Tuberculosis. Cancer or tuberculosis are found in pleurisies of different types. Cancer was found in a 43,7% of the serous pleurisies, in a 64% of the seroushemorrhagic, and in a 46% of the hemorrhagic pleurisies. Tuberculosis was found in a 15,6 % of the serous, in a 7,14 % of the seroushemorrhagic and in a 15,7 % of the purulent. In one case of hemorrhagic pleurisy in which the diagnosis of tuberculosis was not made, further studies confirmed it. The authors point to the existence of non specific pleuritis without neoplastic infiltration in some pleurisies consecutive to lung tumors or from other organs and to its therapeutic consequences. They also inform having found tuberculosis in patients over 50 years of age (8 in 11 cases). In this series the youngest pleural cancer case was a 27 years old man.

  10. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    USDA-ARS?s Scientific Manuscript database

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  11. [Delayed cord clamping in the interest of the newborn child].

    PubMed

    Scherjon, S A; Smit, Y

    2008-06-21

    The importance of delayed cord clamping, both for the preterm and for the term newborn, for the prevention ofneonatal anaemia (during the neonatal period and/or at the age of3 months) and furthermore to reduce the need of blood transfusions, has recently been demonstrated in controlled clinical studies and meta-analyses. Physiological and pathophysiological factors also provide a rationale for delayed cord clamping: neonatal blood volume may increase by 32% if cord clamping is delayed until the umbilical cord has completely stopped pulsating. A slow transition, involving closure of the ductus arteriosus and the foramen ovale cordis and gradual filling of the neonatal systemic circulation, contributes to the opening of the alveoli due to perfusion of the alveolar capillaries. No disadvantages, such as polycythaemia or hyperbilirubinaemia, have been described with regard to preterm neonates, whereas the incidence of intracranial haemorrhages is reduced. Also for the mother, no disadvantages of late clamping have been determined. As a standard procedure, the baby's umbilical cord should not be clamped until at least 3 minutes have passed. One should wait at least 30 seconds during the birth of children for whom a more active approach is necessary. Of all people, these children will benefit from a good Hb level.

  12. Dynamic Clamp in Cardiac and Neuronal Systems Using RTXI

    PubMed Central

    Ortega, Francis A.; Butera, Robert J.; Christini, David J.; White, John A.; Dorval, Alan D.

    2016-01-01

    The injection of computer-simulated conductances through the dynamic clamp technique has allowed researchers to probe the intercellular and intracellular dynamics of cardiac and neuronal systems with great precision. By coupling computational models to biological systems, dynamic clamp has become a proven tool in electrophysiology with many applications, such as generating hybrid networks in neurons or simulating channelopathies in cardiomyocytes. While its applications are broad, the approach is straightforward: synthesizing traditional patch clamp, computational modeling, and closed-loop feedback control to simulate a cellular conductance. Here, we present two example applications: artificial blocking of the inward rectifier potassium current in a cardiomyocyte and coupling of a biological neuron to a virtual neuron through a virtual synapse. The design and implementation of the necessary software to administer these dynamic clamp experiments can be difficult. In this chapter, we provide an overview of designing and implementing a dynamic clamp experiment using the Real-Time eXperiment Interface (RTXI), an open- source software system tailored for real-time biological experiments. We present two ways to achieve this using RTXI’s modular format, through the creation of a custom user-made module and through existing modules found in RTXI’s online library. PMID:25023319

  13. Automated ion channel screening: patch clamping made easy.

    PubMed

    Farre, Cecilia; Stoelzle, Sonja; Haarmann, Claudia; George, Michael; Brüggemann, Andrea; Fertig, Niels

    2007-04-01

    Efficient high resolution techniques are required for screening efforts and research targeting ion channels. The conventional patch clamp technique, a high resolution but low efficiency technique, has been established for 25 years. Recent advances have opened up new possibilities for automated patch clamping. This new technology meets the need of drug developers for higher throughput and facilitates new experimental approaches in ion channel research. Specifically, Nanion's electrophysiology workstations, the Port-a-Patch and the Patchliner, have been successfully introduced as high-quality automated patch clamp platforms for industry as well as academic users. Both platforms give high quality patch clamp recordings, capable of true giga-seals and stable recordings, accessible to the user without the need for years of practical training. They also offer sophisticated experimental possibilities, such as accurate and fast ligand application, temperature control and internal solution exchange. This article describes the chip-based patch clamp technology and its usefulness in ion channel drug screening and academic research.

  14. Axon voltage-clamp simulations. I. Methods and tests.

    PubMed Central

    Moore, J W; Ramón, F; Joyner, R W

    1975-01-01

    This is the first in a series of four papers in which we present the numerical simulation of the application of the voltage clamp technique to excitable cells. In this paper we describe the application of the Crank-Nicolson (1947) method for the solution of the parabolic partial differential equations that describe a cylindrical cell in which the ionic conductances are functions of voltage and time (Hodgkin and Huxley, 1952). This method is compared with other methods in terms of accuracy and speed of solution for a propagated action potential. In addition, differential equations representing a simple voltage-clamp electronic circuit are presented. Using the voltage clamp circuit equations, we simulate the voltage clamp of a single isopotential membrane patch and show how the parameters of the circuit affect the transient response of the patch to a step change in the control potential.The stimulation methods presented in this series of papers allow the evaluation of voltage clamp control of an excitable cell or a syncytium of excitable cells. To the extent that membrane parameters and geometrical factors can be determined, the methods presented here provide solutions for the voltage profile as a function of time. PMID:1174640

  15. Photodynamic Diagnosis Using 5-Aminolevulinic Acid in 41 Biopsies for Primary Central Nervous System Lymphoma.

    PubMed

    Yamamoto, Tetsuya; Ishikawa, Eiichi; Miki, Shunichiro; Sakamoto, Noriaki; Zaboronok, Alexander; Matsuda, Masahide; Akutsu, Hiroyoshi; Nakai, Kei; Tsuruta, Wataro; Matsumura, Akira

    2015-11-01

    We evaluated the feasibility of 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) in the biopsy for primary central nervous system lymphoma (PCNSL). 5-ALA (20 mg kg(-1) ) was administered orally 4 hours preoperatively. Forty-one biopsies obtained under PDD in 47 consecutive biopsies (46 patients) that were finally pathologically diagnosed as PCNSL were evaluated. Positive fluorescence was observed in 34 of those 41 biopsies (82.9%). An intraoperative pathological diagnosis (IOD) of suspected PCNSL was made in 21 of the biopsies with positive fluorescence (61.8%). However, the eight IODs in the remaining 13 biopsies (23.5%) were not correct (atypical cell, 4; high-grade glioma, 1; gliosis, 1; unremarkable, 2). In those 8 biopsies, PCNSL was confirmed by the final pathological diagnosis. There was no difference in the mean Mib-1 labeling index between the biopsies with positive fluorescence (86.5%) and those without positive fluorescence (90.0%). IOD was not performed in 6 biopsies; however, 5 of those biopsies (83.3%) showed positive fluorescence and were finally pathologically diagnosed as PCNSL. Use of PDD in biopsies for patients with suspected PCNSL is a reliable way of obtaining specimens of adequate quality for the final pathological diagnosis and may lead to improved diagnostic yield in the biopsy of PCNSL.

  16. Suction-modified needle biopsy technique for the human soleus muscle.

    PubMed

    Cotter, Joshua A; Yu, Alvin; Kreitenberg, Arthur; Haddad, Fadia H; Baker, Michael J; Fox, John C; Adams, Gregory R

    2013-10-01

    The needle biopsy technique for the soleus muscle is of particular interest because of the muscle's unique fiber type distribution, contractile properties, and sensitivity to unloading. Unlike other commonly biopsied muscles, the soleus is not fully superficial and is in close proximity to neurovascular structures, resulting in a more challenging biopsy. Because of this, a standardized protocol for performing needle biopsies on the human soleus muscle that is safe, reliable, and repeatable is presented. Ultrasonography was used on an initial set of 12 subjects to determine the optimal biopsy zone, thereby guiding the location of the incision site. There were 45 subjects recruited who attended 2 separate biopsy sessions. Each biopsy session incorporated 3 passes of the biopsy needle proximal, posterior, and distal using suction from a portable vacuum source producing 3 separate muscle specimens. There were 84 soleus muscle biopsy procedures which were successfully conducted yielding 252 total samples without complication. Ultrasonography was used to confirm biopsy needle infiltration of the soleus muscle. Average sample weight obtained per pass was 61.5 +/- 15.7 mg. Histochemistry and molecular analyses demonstrated a considerably higher amount of slow type I MHC in comparison to the vastus lateralis, providing verification for the successful sampling of the soleus muscle. The procedure presented consists of a detailed protocol to accurately and consistently obtain muscle biopsy samples from the human soleus muscle. We have demonstrated that the human soleus biopsy is a safe, reliable, and repeatable procedure providing ample tissue for multiple types of analyses.

  17. Effect of sterilization on stiffness and dimensional stability of rubber-dam clamps.

    PubMed

    Giebink, D L; Mathieu, G P; Hondrum, S O

    1996-01-01

    Simulated clinical conditions were used to test the effect of sterilization on rubber-dam clamp stiffness and dimension. Sixty Hygienic and Ivory W7 clamps were either steam or dry heat sterilized and compared to controls. Stiffness and dimensional change between Ivory clamp groups was significant (p<.0001); the sterilized clamps showed less change than the controls. Hygienic groups showed a significant different between the control and dry heat groups (p<.05); the sterilized clamps showed less change than the controls. The change in stiffness and interjaw width for all Ivory clamps compared to all Hygienic clamps was significant (p<.0001). The Hygienic clamps changes less than the Ivory clamps. The results indicate that steam and dry heat sterilization do not affect retention of rubber-dam clamps.

  18. The current role of percutaneous needle biopsies of renal tumours.

    PubMed

    Volpe, Alessandro; Terrone, Carlo; Scarpa, Roberto M

    2009-06-01

    The role of percutaneous biopsy of renal masses has been traditionally limited by concerns about its safety, accuracy and sampling errors. The increasing incidence in the diagnosis of incidental small renal masses (SRMs), the development of conservative and minimally invasive treatments for low risk renal cell carcinomas (RCCs) and the discovery of novel targeted treatments for metastatic disease are now leading to wider indications for renal tumor biopsy. Percutaneous biopsy of renal tumors can be performed in an outpatient setting under ultrasound and/or CT guidance. 18 gauge needles loaded in an automatic biopsy gun are used to retrieve cores and 21 gauge needles to obtain FNA specimens through a 17 gauge coaxial cannula placed close to the tumor. A careful check of the quality of biopsies and aspirates is paramount to maximize the diagnostic yield of the procedure. With the development of new biopsy techniques the risk of tumor seeding appears negligible and significant bleeding is unusual and very rarely clinically significant. In centres with expertise, needle core biopsy with or without FNA can provide adequate specimens for an accurate diagnosis in over 90% of cases. Incidental SRMs are frequently detected in elderly patients and have a very heterogeneous biological behaviour At surgery up to one third have benign histologies and most of those that are malignant are low grade RCCs. Pretreatment percutaneous biopsy can significantly decrease the number of unnecessary surgeries for benign disease and assist the urologist in clinical decision making, especially for elderly and unfit patients who are possible candidates for active surveillance and/or minimally invasive ablative therapies. Finally, there is potential for stratifying initial therapy of metastatic RCC by histological subtype on needle biopsies.

  19. The intercostal nerve as a target for diagnostic biopsy.

    PubMed

    Nguyen, Khoi D; Choudhri, Haroon F; Macomson, Samuel D

    2017-05-12

    OBJECTIVE Peripheral nerve biopsy is a useful tool in diagnosing peripheral neuropathies. Sural and gracilis nerves have become the most common targets for nerve biopsy. However, the yield of sural nerve biopsy is limited in patients who have motor neuropathies, and gracilis nerve biopsy presents technical challenges and increased complications. The authors propose the intercostal nerve as an alternative motor nerve target for biopsy. METHODS A total of 4 patients with suspected peripheral neuropathies underwent intercostal nerve biopsy at the authors' institution. A rib interspace that is inferior to the pectoralis muscle and anterior to the anterior axillary line is selected for the procedure. Generally the lower intercostal nerves (i.e., T7-11) are targeted. An incision is made over the inferior aspect of the superior rib at the chosen interspace. Blunt dissection is carried down to the neurovascular bundle and the nerve is isolated, ligated, and cut to send for pathological examination. RESULTS The average operative time for all cases was 73 minutes, with average blood loss of 8 ml. Biopsy results from 1 patient exhibited axonopathy, and the other 3 patients demonstrated axonopathy with demyelination. There were no short- or long-term postoperative complications. None of the patients reported sensory or motor deficits related to the biopsy at 6 weeks postoperatively. CONCLUSIONS The intercostal nerve can be an alternative target for biopsy, especially in patients with predominantly motor neuropathies, due to its mixed sensory and motor fibers, straightforward anatomy, minimal risk of serious sensory deficits, and no risk of motor impairment.

  20. Biopsy: Types of Biopsy Procedures Used to Diagnose Cancer

    MedlinePlus

    ... A biopsy also helps your doctor determine how aggressive your cancer is — the cancer's grade. The grade ... grade (grade 1) cancers are generally the least aggressive and high-grade (grade 4) cancers are generally ...

  1. Should Hypoechoic Lesions on Transrectal Ultrasound Be Sampled During Magnetic Resonance Imaging-targeted Prostate Biopsy?

    PubMed

    Shakir, Nabeel A; Siddiqui, M Minhaj; George, Arvin K; Kongnyuy, Michael; Ho, Richard; Fascelli, Michele; Merino, Maria J; Turkbey, Baris; Choyke, Peter L; Wood, Bradford J; Pinto, Peter A

    2017-07-01

    To determine whether supplemental biopsy of hypoechoic ultrasound lesions (HUL) incidentally found during magnetic resonance imaging (MRI)-transrectal ultrasound (TRUS) fusion-targeted prostate biopsy results in improved prostate cancer (PCa) detection. Patients underwent MRI-TRUS-targeted biopsy as part of an ongoing prospective trial from August 2007 to February 2015. For men with HUL, the biopsy pathology of HUL and MRI lesions was classified according to the updated 2014 International Society of Urological Pathology (ISUP) grading system. The detection of PCa by MRI-targeted biopsy with and without HUL biopsy was compared. Of 1260 men in the trial, 106 underwent biopsy of 119 HULs. PCa was diagnosed in 52 out of 106 men (49%) by biopsy of either MRI lesions or HUL. Biopsy of HUL in addition to MRI lesions resulted in 4 additional diagnoses of high-grade (ISUP grades 3-5) PCa versus biopsy of MRI lesions alone (20 vs 16 men, P = .046). Three of these cases were upgraded from lower grade (ISUP grades 1-2) PCa on MRI-guided biopsy alone, and only 1 case (1% of cohort) was diagnosed that would have been missed by MRI-guided biopsy alone. Supplemental biopsy of HUL did not change the PCa risk category in 96% (102 out of 106) of men with HUL. Supplemental biopsy of HUL yields a small increase in the detection of higher grade PCa as compared with biopsy of MRI lesions alone. As upgrading is rare, routinely screening for HUL during MRI-targeted biopsy remains controversial. Copyright © 2016. Published by Elsevier Inc.

  2. Systematic 5 region prostate biopsy is superior to sextant method for diagnosing carcinoma of the prostate.

    PubMed

    Eskew, L A; Bare, R L; McCullough, D L

    1997-01-01

    The number of patients undergoing prostate biopsy has dramatically increased due to prostate specific antigen screening. The low specificity of this screening tool requires prostate biopsy for diagnosis of prostate cancer. The sextant biopsy technique has been used widely with success in diagnosing carcinoma of the prostate. However, concern has arisen that the original sextant method may not include an adequate sampling of the prostate. For many years we have used a method of prostate biopsy that, in addition to sextant biopsies, takes additional biopsies in a systematic fashion, which we call the 5 region prostate biopsy. We conducted a prospective study to determine if our 5 region prostate biopsy technique significantly increases the chances of finding carcinoma of the prostate compared to the sextant biopsy technique. A total of 119 patients underwent transrectal ultrasound guided needle biopsy of the prostate. In addition to sextant biopsies, cores were taken from the far lateral and mid regions of the gland. Pathological findings of the additional regions were compared to those of the sextant regions. Of the 48 patients with prostate cancer 17 (35%) had carcinomas only in the additional regions, which would have remained undetected had the sextant biopsy technique been used alone (p < 0.05). Of these additional cancers 83% had Gleason scores of 6 or more. We introduce the 5 region technique of prostate biopsy as a means of significantly increasing the diagnostic yield of prostate biopsy in finding carcinoma of the prostate. We have found this technique to be safe, efficacious and superior to the sextant method of biopsy in identifying prostate cancer at an early but significant stage. The greatest use of the 5 region biopsy technique is in patients who have prostate specific antigen levels between 4 and 10 ng./ml.

  3. [Pulmonary needle biopsy in children].

    PubMed

    Gerbeaux, J

    1975-01-01

    Pulmonary biopsy done with a needle of circular bore, can be performed on very young children. A sample of tissue, big enough to establish a precise diagnosis in 2/3 of cases, can be obtained. The main complication is pneumothorax occuring about once in five. Hemoptysia or hemorrhage has never been observed. A proposed indication of premortem biopsy accelerated the death of a child with congenital pulmonary fibrosis. The search of a diagnosis in diffuse pulmonary diseases is the major indication for pulmonary biopsy in the child.

  4. Contemporary frameless intracranial biopsy techniques: Might variation in safety and efficacy be expected?

    PubMed

    Verploegh, Iris S C; Volovici, Victor; Haitsma, Iain K; Schouten, Joost W; Dirven, Clemens M; Kros, Johan M; Dammers, Ruben

    2015-11-01

    Frameless stereotactic neuronavigation has proven to be a feasible technology to acquire brain biopsies with good accuracy and little morbidity and mortality. New systems are constantly introduced into the neurosurgical armamentarium, although few studies have actually evaluated and compared the diagnostic yield, morbidity, and mortality of various manufacturer's frameless neuronavigation systems. The present study reports our experience with brain biopsy procedures performed using both the Medtronic Stealth Treon(TM) Vertek® and BrainLAB® Varioguide frameless stereotactic brain biopsy systems. All 247 consecutive biopsies from January 2008 until May 2013 were evaluated retrospectively. One hundred two biopsies each were performed using the Medtronic (2008-2009) and BrainLAB® system (2011-2013), respectively. The year 2010 was considered a transition year, in which 43 biopsies were performed with either system. Patient demographics, perioperative characteristics, and histological diagnosis were reviewed, and a comparison was made between the two brain biopsy systems. The overall diagnostic yield was 94.6 %, i.e., 11 biopsies were nondiagnostic, 5 (4.9 %) with the Medtronic and 6 (5.9 %) with the BrainLAB® system. No differences besides the operating time (108 vs 120 min) were found between the two biopsy methods. On average, 6.6 tissue samples were taken with either technique. Peri- and postoperative complications were seen in 5.3 % and 12.9 %, consisting of three symptomatic hemorrhages (1.2 %). Biopsy-related mortality occurred in 0.8 % of all biopsies. Regarding diagnostic yield, complication rate, and biopsy-related mortality, there seems to be no difference between the frameless biopsy technique from Medtronic and BrainLAB®. In contemporary time, the neurosurgeon has many tools to choose from, all with a relatively fast learning curve and ever improving feasibility. Thus, the issue of choice involves not the results, but the familiarity, end

  5. Umbilical cord clamping. An analysis of a usual neonatological conduct.

    PubMed

    Papagno, L

    1998-01-01

    Here we described a critical analysis of the neonatological procedure of early cord clamping, meaning this, within 40 seconds after birth. Fifty three cases are here analysed, in which this practice was not performed, but instead a late umbilical cord clamping was done after birth or after the cord had stopped beating. Variations in hematocrito values within 24 to 36 hours after birth were studied. A transitory polycithemia, with a maximum peak 12 hours post-delivery was observed. These values returned to normal levels between 24 and 36 hours after birth. K vitamin was not administered to any of the newborns. No pathology appeared related to this transitory polycithemia. In can be concluded that the late umbilical cord clamping represents no risk to the new-born and that the pathological phenomena described under these circumstances may be attributed to the increase in K vitamin dependent coagulation factors that are induced by the routinary administration of phitonadione to all normal newborns.

  6. Using physiology to guide time to cord clamping.

    PubMed

    Kluckow, Martin; Hooper, Stuart B

    2015-08-01

    Immediate clamping and cutting of the umbilical cord at birth has been the accepted standard of care for decades. The physiologic rationale relating umbilical cord clamping (UCC) to the events of the circulatory transition is not considered in arbitrarily recommended cord clamping times. Systematic review of early versus deferred UCC shows significant hemodynamic benefits to the deferred group. Mechanisms for this protective effect are considered in this review. The original concept of a placental transfusion with a volume load and prevention of low cardiac output relies on the physiological end point of the amount of blood transfused. The newer concept of an ordered physiological transition is increasingly supported. This model places aeration of the lungs and an increase in pulmonary blood flow back at the centre of the circulatory transition with timing of UCC being related to establishment of respiration. The need for "physiologically based" UCC is discussed. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  7. [Advantage of delayed umbilical cord clamping in the newborn infant].

    PubMed

    Menget, A; Mougey, C; Thiriez, G; Riethmuller, D

    2013-09-01

    The timing of umbilical cord clamping remains controversial. Although most maternity wards use the early clamping (5-15s), randomized studies and meta-analyses have demonstrated the benefit of delayed clamping for term and preterm newborn infants over the past 10 years. Indeed, placentofetal transfusion of 20-30 ml/kg in 2-3 min improves the iron status of term infants and prevents infant hypochromic anemia. Infant anemia is a public health problem in many developing countries. For preterm newborns, placental transfusion for 45 s or milking the cord for 15 s improves cardiovascular adaptation, with better hemodynamic stability, as well as decreased intraventricular hemorrhages, need for transfusion, and late-onset sepsis. A new look at this symbolic act is needed and professionals need to be persuaded of the importance of the "wait a minute" policy for a better physiological delivery.

  8. Fluoroscopy-guided intervertebral disc biopsy with a coaxial drill system.

    PubMed

    Wallace, Adam N; Pacheco, Rafael A; Vyhmeister, Ross; Tomasian, Anderanik; Chang, Randy O; Jennings, Jack W

    2016-02-01

    Percutaneous biopsy of discitis-osteomyelitis is performed to isolate the causative microorganism and exclude alternative diagnoses. We compared drill-assisted and manual fluoroscopy-guided intervertebral disc biopsies with respect to conscious sedation requirements and histologic quality of obtained specimens. Medical records of all single-level, fluoroscopy-guided intervertebral disc biopsies supervised by one of two musculoskeletal radiologists between January 2010 and March 2015 were reviewed. Duration and cumulative medication doses required for each biopsy were recorded. Pathology reports were reviewed to determine whether the obtained specimens were adequate for histopathologic evaluation. Microbiology reports were reviewed to determine whether the causative organism was isolated from the biopsy specimen. During the study period, 21 drill-assisted and 20 manual biopsies were performed. The median duration of conscious sedation for drill-assisted biopsies was 30 min (range, 17-40 min) compared with 39 min (range, 20-90 min) for manual biopsies (p < 0.01). Drill-assisted biopsies also required lower median cumulative doses of intravenous midazolam [2 mg (range, 0-5 mg) vs. 3 mg (range, 0-9 mg); p = 0.02]. All drill-assisted biopsy specimens were adequate for histopathologic evaluation. One manual biopsy specimen (5 %; 1/20) was inadequate for histopathologic evaluation owing to crush artifact. The microbiology yields of drill-assisted and manual biopsies were comparable [14 % (3/21) vs. 20 % (4/20); p = 0.62]. Fluoroscopically-guided intervertebral disc biopsies performed with drill assistance require less conscious sedation compared with manual biopsies and yield specimens that are adequate for histopathologic evaluation.

  9. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    SciTech Connect

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  10. Needle Biopsy of the Lung

    MedlinePlus

    ... than surgical biopsy and may not require general anesthesia. Tell your doctor about any recent illnesses or ... and whether you have any allergies, especially to anesthesia. Discuss any medications you’re taking, including herbal ...

  11. [Optimized standards for prostate biopsy].

    PubMed

    Wullich, B; Füssel, S; Grobholz, R

    2007-06-01

    As individual risk assessment mainly depends on the correct prediction of the tumor's biological behavior, primary diagnosis plays a key role in the clinical management of prostate cancer patients. Prostate core needle biopsy, as a primary diagnostic tool, should not only confirm clinical suspicion but also supply the urologist with information which is necessary for risk-adapted therapy. The experience and competence of both the urologist and the pathologist are crucial for the quality of prostate core needle biopsy diagnosis. Optimized handling and submission of prostate core needle biopsy specimens by the urologist to the pathologist are of outstanding importance for improving the number of cancer cases detected. Increasing availability of molecular markers leads to the necessity of developing new tissue sampling procedures which allow prostate core needle biopsy specimens to be simultaneously studied histologically and by molecular approaches.

  12. Endomyocardial biopsy-integrating electrode at the bioptome tip.

    PubMed

    Konecny, Tomas; Noseworthy, Peter A; Kapa, Suraj; Cooper, Leslie T; Mulpuru, Siva K; Sandhu, Gurpreet S; Asirvatham, Samuel

    2015-06-01

    The addition of electroanatomic mapping to a standard echo-guided endomyocardial biopsy could identify areas of abnormal pathology and increase the diagnostic yield of the procedure. In this demonstration of a novel technique, a 45-year-old woman with clinical suspicion for cardiac sarcoidosis underwent right ventricular bipolar electroanatomical mapping with identification of areas of signal fractionation and low voltage. A bioptome, configured to record an electrogram from the tip, was then visualized on the three-dimensional electroanatomic mapping (3DEAM) system, and directed to these areas. The biopsy was assisted by the use of a steerable introducer sheath, and by recording unipolar and extended bipolar signals from the bioptome tip. A prominent change in the signal was detected by the electrode at the bioptome tip when the jaws closed on the endomyocardial tissue. Patient tolerated the procedure without complications, and the biopsied samples were appropriate for pathological analysis. Using existing technology, the 3DEAM, which integrates unipolar and bipolar signal from the bioptome tip, is feasible, and can be safely added to a standard echocardiographically guided endomyocardial biopsy. Future studies should investigate whether such a technique could increase the safety and diagnostic yield of endomyocardial biopsies in patients with suspected cardiomyopathies. © The Author(s), 2015.

  13. Comparison of feline core bone marrow biopsies from different sites using 2 techniques and needles.

    PubMed

    Abrams-Ogg, Anthony C G; Defarges, Alice; Bienzle, Dorothee

    2014-03-01

    Commonly used 11ga or 13ga biopsy needles are relatively large for cats and often preclude successful collection of bone marrow (BM) core biopsies. The objective was to compare 15ga to 13ga BM core biopsy ease of collection and specimen quality. In 10 cats, humeral biopsies obtained with 15ga EZ-IO needles were compared with iliac biopsies obtained with 13ga Jamshidi needles. Body condition, ease of collection, section quality, postprocedure pain, and swelling at biopsy sites were scored. Specimen length on mounted slides was measured and specimens with quality scores of 3-5 out of a maximum value of 5 were considered to be of acceptable diagnostic quality. The distribution of all parameters was assessed by Shapiro-Wilk tests, and differences in parameters were assessed by ANCOVA. There were no significant differences between 15ga and 13ga biopsies, except that the 15ga humeral biopsy was judged to be easier to perform than 13ga iliac biopsy, and there was more severe postbiopsy swelling with 13ga biopsies. Facility score (mean ± SD), section quality score (median ± SD) and specimen length (mm, mean ± SD) were 12.7 ± 2.3, 2.0 ± 1.4, and 6.0 ± 2.1 for 15ga biopsies, respectively, and 8.9 ± 2.4, 1.0 ± 1.8, and 7.5 ± 2.5 for 13ga biopsies, respectively. Three specimens of acceptable quality were obtained with each 15ga and 13ga biopsies. In cats, BM biopsy of the humerus with a 15ga needle is easier and causes less postbiopsy swelling than biopsy of the ilium with a 13ga needle. Sites and needles are equivalent with respect to yielding specimens of acceptable quality. Neither technique consistently captured high-quality specimens. ©2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

  14. How to Interpret Thyroid Biopsy Results: A Three-Year Retrospective Interventional Radiology Experience

    SciTech Connect

    Oppenheimer, Jason D. Kasuganti, Deepa; Nayar, Ritu; Chrisman, Howard B.; Lewandowski, Robert J.; Nemcek, Albert A.; Ryu, Robert K.

    2010-08-15

    Results of thyroid biopsy determine whether thyroid nodule resection is appropriate and the extent of thyroid surgery. At our institution we use 20/22-gauge core biopsy (CBx) in conjunction with fine-needle aspiration (FNA) to decrease the number of passes and improve adequacy. Occasionally, both ultrasound (US)-guided FNA and CBx yield unsatisfactory specimens. To justify clinical recommendations for these unsatisfactory thyroid biopsies, we compare rates of malignancy at surgical resection for unsatisfactory biopsy results against definitive biopsy results. We retrospectively reviewed a database of 1979 patients who had a total of 2677 FNA and 663 CBx performed by experienced interventional radiologists under US guidance from 2003 to 2006 at a tertiary-care academic center. In 451 patients who had surgery following biopsy, Fisher's exact test was used to compare surgical malignancy rates between unsatisfactory and malignant biopsy cohorts as well as between unsatisfactory and benign biopsy cohorts. We defined statistical significance at P = 0.05. We reported an overall unsatisfactory thyroid biopsy rate of 3.7% (100/2677). A statistically significant higher rate of surgically proven malignancies was found in malignant biopsy patients compared to unsatisfactory biopsy patients (P = 0.0001). The incidence of surgically proven malignancy in unsatisfactory biopsy patients was not significantly different from that in benign biopsy patients (P = 0.8625). In conclusion, an extremely low incidence of malignancy was associated with both benign and unsatisfactory thyroid biopsy results. The difference in incidence between these two groups was not statistically significant. Therefore, patients with unsatisfactory biopsy specimens can be reassured and counseled accordingly.

  15. Image guided core needle biopsy of musculoskeletal lesions: are nondiagnostic results clinically useful?

    PubMed

    Didolkar, Manjiri M; Anderson, Megan E; Hochman, Mary G; Rissmiller, Julia G; Goldsmith, Jeffrey D; Gebhardt, Mark G; Wu, Jim S

    2013-11-01

    The clinical utility of nondiagnostic core needle biopsies is not fully understood. Understanding the clinical and radiologic factors associated with nondiagnostic core needle biopsies may help determine the utility of these nondiagnostic biopsies and guide clinical decision making. We asked (1) whether benign or malignant bone and soft tissue lesions have a higher rate of nondiagnostic core needle biopsy results, and which diagnoses have the lowest diagnostic yield; (2) how often nondiagnostic results affected clinical decision-making; and (3) what clinical factors are associated with nondiagnostic but useful core needle biopsies. A retrospective study was performed of 778 consecutive image-guided core needle biopsies of bone and soft tissue lesions referred to the musculoskeletal radiology department at a single institution. The reference standard was (1) the final diagnosis at surgery or (2) clinical followup. Diagnostic yield was calculated for the most common diagnoses. Clinical and imaging features related to each nondiagnostic core needle biopsy were assessed for their association with clinical usefulness. Useful nondiagnostic biopsies were defined as those that help guide treatment. Each lesion was assessed before biopsy by the orthopaedic oncologist as (1) "likely to be benign" or (2) "suspicious for malignancy." The overall diagnostic yield was 74%. Malignant lesions had higher diagnostic yield than benign lesions: 94% (323 of 345) versus 58% (252 of 433), yielding a relative risk (RR) of 1.61 and 95% CI of 1.48 to 1.75. Soft tissue lesions had a higher diagnostic yield than bone lesions: 82% (291 of 355) versus 67% (284 of 423); RR, 1.22; 95% CI, 1.22 (1.12-1.33). Ganglion cyst (36%, four of 11), myositis ossificans (40%, two of five), Langerhans cell histiocytosis (0%, 0 of four), and simple bone cyst 0%, 0 of six) had the lowest diagnostic yield. Of the nondiagnostic biopsies assessed for clinical usefulness by the orthopaedic oncologist, 60% (85 of

  16. Pleural controversies: image guided biopsy vs. thoracoscopy for undiagnosed pleural effusions?

    PubMed

    Dixon, Giles; de Fonseka, Duneesha; Maskell, Nick

    2015-06-01

    Undiagnosed pleural effusions present an increasing diagnostic burden upon healthcare providers internationally. The investigation of pleural effusions often requires the acquisition of tissue for histological analysis and diagnosis. Historically there were two options for tissue biopsy: a 'gold standard' surgical biopsy or a "blind" closed pleural biopsy. Over the last decade however, image-guided Tru-cut biopsies and local anaesthetic thoracoscopic (local anaesthetic thoracoscopy) biopsies have become more widespread. Image-guided techniques acquire samples under ultrasound (US) or computed tomography (CT) guidance whereas LAT involves the direct visualisation and biopsy of the pleura with pleuroscopy. Both techniques have been shown to be superior to 'blind' closed pleural biopsy for the diagnosis of pleural or metastatic malignancy. However, closed biopsy remains a viable method of investigation in areas of high incidence of tuberculosis (TB). Beyond this, each investigative technique has its own advantages and disadvantages. Image-guided biopsy is less invasive, usually carried out as an outpatient procedure, and enables tissue biopsy in frail patients and those with pleural thickening but no pleural fluid. Local anaesthetic thoracoscopy (LAT) provides diagnostic and therapeutic capabilities in one procedure. Large volume thoracentesis, multiple pleural biopsies and talc poudrage can be carried out in a single procedure. The overall diagnostic yield is similar for both techniques, although there are no large-scale direct comparisons. Both techniques share low complication rates.

  17. Pleural controversies: image guided biopsy vs. thoracoscopy for undiagnosed pleural effusions?

    PubMed Central

    Dixon, Giles; de Fonseka, Duneesha

    2015-01-01

    Undiagnosed pleural effusions present an increasing diagnostic burden upon healthcare providers internationally. The investigation of pleural effusions often requires the acquisition of tissue for histological analysis and diagnosis. Historically there were two options for tissue biopsy: a ‘gold standard’ surgical biopsy or a “blind” closed pleural biopsy. Over the last decade however, image-guided Tru-cut biopsies and local anaesthetic thoracoscopic (local anaesthetic thoracoscopy) biopsies have become more widespread. Image-guided techniques acquire samples under ultrasound (US) or computed tomography (CT) guidance whereas LAT involves the direct visualisation and biopsy of the pleura with pleuroscopy. Both techniques have been shown to be superior to ‘blind’ closed pleural biopsy for the diagnosis of pleural or metastatic malignancy. However, closed biopsy remains a viable method of investigation in areas of high incidence of tuberculosis (TB). Beyond this, each investigative technique has its own advantages and disadvantages. Image-guided biopsy is less invasive, usually carried out as an outpatient procedure, and enables tissue biopsy in frail patients and those with pleural thickening but no pleural fluid. Local anaesthetic thoracoscopy (LAT) provides diagnostic and therapeutic capabilities in one procedure. Large volume thoracentesis, multiple pleural biopsies and talc poudrage can be carried out in a single procedure. The overall diagnostic yield is similar for both techniques, although there are no large-scale direct comparisons. Both techniques share low complication rates. PMID:26150917

  18. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable...

  19. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  20. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  1. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  2. 21 CFR 882.5175 - Carotid artery clamp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Carotid artery clamp. 882.5175 Section 882.5175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... (the principal artery in the neck that supplies blood to the brain) and has a removable adjusting...

  3. Clamp provides efficient connection for high-density currents

    NASA Technical Reports Server (NTRS)

    Mc Carthy, J. R.; Trebes, D. M.

    1967-01-01

    Electrical connector clamp /bus bar/ gives high contact-surface efficiency for providing a high current to thin wall stainless steel tubing containing hydrogen gas. It uses lead solder film to provide the electrical equivalent of a fusion bond without degrading the grain structure, permitting disassembly and reuse of the components.

  4. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Cable clamps and grips. 18.40 Section 18.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  5. 30 CFR 18.40 - Cable clamps and grips.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Cable clamps and grips. 18.40 Section 18.40 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design...

  6. Do not overlook an umbilical cord hernia before clamping.

    PubMed

    Cizmeci, Mehmet Nevzat; Kanburoglu, Mehmet Kenan; Akelma, Ahmet Zulfikar; Tatli, Mustafa Mansur

    2013-08-01

    An umbilical cord hernia is a rare midline abdominal defect. These masses may be easily overlooked at birth, which may result in an intestinal injury due to careless proximal application of the cord clamp. Herein, we present a newborn infant with an umbilical cord hernia who was managed by primary closure of the lesion.

  7. Beyond the patch clamp: nanotechnologies for intracellular recording.

    PubMed

    Kruskal, Peter B; Jiang, Zhe; Gao, Teng; Lieber, Charles M

    2015-04-08

    The patch clamp is a fundamental tool for neuroscientists, offering insights that have shaped our understanding of the brain. Advances in nanotechnology suggest that the next generation of recording methods is now within reach. We discuss the complexity and future promise of applying nanoscience to neural recording. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Robotic partial nephrectomy with selective parenchymal compression (Simon clamp).

    PubMed

    Castillo, O A; Rodriguez-Carlin, A; Lopez-Fontana, G; Aleman, E

    2013-01-01

    To present our initial experience using selective renal parenchymal ischemia, without hilar clamping, in robotic-assisted partial nephrectomy. In four patients with T1a renal tumor we performed robotic-assisted partial nephrectomy, using the Simon's clamp (Aesculap). It provides selective parenchymal compression without the need of vascular clamping. All patients had exofitic renal tumors in polar location. Renal parenchymal reconstruction was done as the standard technique. The median age was 49.6 years (42-59), 3 male and 1 female patient. Median operative time was 71,6 minutes (40-120). Mean stimated bleeding was 250 ml (50-400). Average tumor size was 3,25 cm (1,5-5,3). There were no complications and the average hospital stay was 3,5 days (1-7). The pathology was informed as renal cell carcinoma in three patients and one hemorrhagic cyst. The surgical margins were negative. Our preliminary results shows that selective renal parenchymal compression, with the Simon's clamp, provides an alternative to vascular control in selected patients with polar renal tumors. Copyright © 2012 AEU. Published by Elsevier Espana. All rights reserved.

  9. A band clamp with a spring toggle lever

    NASA Technical Reports Server (NTRS)

    Simmonds, M.

    1974-01-01

    Clamp could have several applications, as it provides tolerance for both expansion and contraction. It might be useful with firemen's breathing apparatus and luggage racks and other freight-carrying equipment. Also, using same piece as handle and spring reduces production costs by reducing number of parts.

  10. Targeted fascicular biopsy of the brachial plexus: rationale and operative technique.

    PubMed

    Laumonerie, Pierre; Capek, Stepan; Amrami, Kimberly K; Dyck, P James B; Spinner, Robert J

    2017-03-01

    OBJECTIVE Nerve biopsy is useful in the management of neuromuscular disorders and is commonly performed in distal, noncritical cutaneous nerves. In general, these procedures are diagnostic in only 20%-50%. In selected cases in which preoperative evaluation points toward a more localized process, targeted biopsy would likely improve diagnostic yield. The authors report their experience with targeted fascicular biopsy of the brachial plexus and provide a description of the operative technique. METHODS All cases of targeted biopsy of the brachial plexus biopsy performed between 2003 and 2015 were reviewed. Targeted nerve biopsy was performed using a supraclavicular, infraclavicular, or proximal medial arm approach. Demographic data and clinical presentation as well as the details of the procedure, adverse events (temporary or permanent), and final pathological findings were recorded. RESULTS Brachial plexus biopsy was performed in 74 patients (47 women and 27 men). The patients' mean age was 57.7 years. All patients had abnormal findings on physical examination, electrodiagnostic studies, and MRI. The overall diagnostic yield of biopsy was 74.3% (n = 55). The most common diagnoses included inflammatory demyelination (19), breast carcinoma (17), neurolymphomatosis (8), and perineurioma (7). There was a 19% complication rate; most of the complications were minor or transient, but 4 patients (5.4%) had increased numbness and 3 (4.0%) had additional weakness following biopsy. CONCLUSIONS Targeted fascicular biopsy of the brachial plexus is an effective diagnostic procedure, and in highly selected cases should be considered as the initial procedure over nontargeted, distal cutaneous nerve biopsy. Using MRI to guide the location of a fascicular biopsy, the authors found this technique to produce a higher diagnostic yield than historical norms as well as providing justification for definitive treatment.

  11. Multicenter study for the evaluation of a dedicated biopsy device for MR-guided vacuum biopsy of the breast.

    PubMed

    Perlet, C; Heinig, A; Prat, X; Casselman, J; Baath, L; Sittek, H; Stets, C; Lamarque, J; Anderson, I; Schneider, P; Taourel, P; Reiser, M; Heywang-Köbrunner, S H

    2002-06-01

    The purpose of this multicenter study was to determine the accuracy and clinical value of a dedicated breast biopsy system which allows for MR-guided vacuum biopsy (VB) of contrast-enhancing lesions. In five European centers, MR-guided 11-gauge VB was performed on 341 lesions. In 7 cases VB was unsuccessful. This was immediately realized on postinterventional images or direct follow-up combined with histopathology-imaging correlation; thus, a false-negative diagnosis was avoided. Histology of 334 successful biopsies yielded 84 (25%) malignancies, 17 (5%) atypical ductal hyperplasias, and 233 (70%) benign entities. Verification of malignant or borderline lesions included reexcision of the biopsy cavity. Benign histologic biopsy results were verified by retrospective correlation with the pre- and postinterventional MRI and by subsequent follow-up. Our results indicate that MR-guided VB, in combination with the dedicated biopsy coil, offers the possibility to accurately diagnose even very small lesions that can only be visualized or localized by MRI.

  12. [Liquid Biopsy and Laboratory Medicine].

    PubMed

    Furuta, Koh

    2015-09-01

    Recent progress in cancer biology has revealed the fact that molecular profiles of primary and metastatic cancer are not necessarily the same. Furthermore, evidence of intra-tumor heterogeneity has been disclosed repeatedly. In addition to these, acquiring resistances to chemoradiation therapy is far more rapid than typical predictions. Under these circumstances, physicians are realizing that one biopsy is not enough to predict the direction of cancer progression or extension. Repeated biopsy was proposed in this context. For "re-biopsy", acquiring blood is much easier compared to regular biopsies of acquiring body tissues. Therefore, CTC or Cell-free DNA is one of the hot topics in clinical and molecular diagnostic fields. The term "liquid biopsy" is used to include these two materials. We utilized a CTC isolation device based on microfluidic principles. Procedures for the extraction of DNA from plasma (Cell-free DNA) is also available. Based on this background, we performed a feasibility study of NGS (Next Generation Sequencing) by analyzing materials from advanced gastrointestinal cancer patients. We have successfully acquired NGS results using these liquid biopsies. We have also investigated the possibility of storing CTCs by evaluating procedures after cytospin using H1975 cells with various fixation conditions under a DIC microscope examination. Because of the paucity of the number of isolated CTCs, H1975 cells were used for this purpose. After cytospin, 95% ETOH and then -80 degrees C storage provided the best results. Attempts at not only NGS but also storage in this sequence of studies have opened new fields of liquid biopsy in clinical laboratories.

  13. An improved vaseline gap voltage clamp for skeletal muscle fibers

    PubMed Central

    1976-01-01

    A Vaseline gap potentiometric recording and voltage clamp method is developed for frog skeletal muscle fibers. The method is based on the Frankenhaeuser-Dodge voltage clamp for myelinated nerve with modifications to improve the frequency response, to compensate for external series resistance, and to compensate for the complex impedance of the current-passing pathway. Fragments of single muscle fibers are plucked from the semitendinosus muscle and mounted while depolarized by a solution like CsF. After Vaseline seals are formed between fluid pools, the fiber ends are cut once again, the central region is rinsed with Ringer solution, and the feedback amplifiers are turned on. Errors in the potential and current records are assessed by direct measurements with microelectrodes. The passive properties of the preparation are simulated by the "disk" equivalent circuit for the transverse tubular system and the derived parameters are similar to previous measurements with microelectrodes. Action potentials at 5 degrees C are long because of the absence of delayed rectification. Their shape is approximately simulated by solving the disk model with sodium permeability in the surface and tubular membranes. Voltage clamp currents consist primarily of capacity currents and sodium currents. The peak inward sodium current density at 5 degrees C is 3.7 mA/cm2. At 5 degrees C the sodium currents are smoothly graded with increasing depolarization and free of notches suggesting good control of the surface membrane. At higher temperatures a small, late extra inward current appears for small depolarizations that has the properties expected for excitation in the transverse tubular system. Comparison of recorded currents with simulations shows that while the transverse tubular system has regenerative sodium currents, they are too small to make important errors in the total current recorded at the surface under voltage clamp at low temperature. The tubules are definitely not under voltage

  14. Rediscovering sperm ion channels with the patch-clamp technique

    PubMed Central

    Kirichok, Yuriy; Lishko, Polina V.

    2011-01-01

    Upon ejaculation, mammalian spermatozoa have to undergo a sequence of physiological transformations within the female reproductive tract that will allow them to reach and fertilize the egg. These include initiation of motility, hyperactivation of motility and perhaps chemotaxis toward the egg, and culminate in the acrosome reaction that permits sperm to penetrate the protective vestments of the egg. These physiological responses are triggered through the activation of sperm ion channels that cause elevations of sperm intracellular pH and Ca2+ in response to certain cues within the female reproductive tract. Despite their key role in sperm physiology and their absolute requirement for the process of fertilization, sperm ion channels remain poorly understood due to the extreme difficulty in application of the patch-clamp technique to spermatozoa. This review covers the topic of sperm ion channels in the following order: first, we discuss how the intracellular Ca2+ and pH signaling mediated by sperm ion channels controls sperm behavior during the process of fertilization. Then, we briefly cover the history of the methodology to study sperm ion channels, which culminated in the recent development of a reproducible whole-cell patch-clamp technique for mouse and human cells. We further discuss the main approaches used to patch-clamp mature mouse and human spermatozoa. Finally, we focus on the newly discovered sperm ion channels CatSper, KSper (Slo3) and HSper (Hv1), identified by the sperm patch-clamp technique. We conclude that the patch-clamp technique has markedly improved and shifted our understanding of the sperm ion channels, in addition to revealing significant species-specific differences in these channels. This method is critical for identification of the molecular mechanisms that control sperm behavior within the female reproductive tract and make fertilization possible. PMID:21642646

  15. Clamped-filament elongation model for actin-based motors.

    PubMed Central

    Dickinson, Richard B; Purich, Daniel L

    2002-01-01

    Although actin-based motility drives cell crawling and intracellular locomotion of organelles and certain pathogens, the underlying mechanism of force generation remains a mystery. Recent experiments demonstrated that Listeria exhibit episodes of 5.4-nm stepwise motion corresponding to the periodicity of the actin filament subunits, and extremely small positional fluctuations during the intermittent pauses [S. C. Kuo and J. L. McGrath. 2000. Nature. 407:1026-1029]. These findings suggest that motile bacteria remain firmly bound to actin filament ends as they elongate, a behavior that appears to rule out previous models for actin-based motility. We propose and analyze a new mechanochemical model (called the "Lock, Load & Fire" mechanism) for force generation by means of affinity-modulated, clamped-filament elongation. During the locking step, the filament's terminal ATP-containing subunit binds tightly to a clamp situated on the surface of a motile object; in the loading step, actin.ATP monomer(s) bind to the filament end, an event that triggers the firing step, wherein ATP hydrolysis on the clamped subunit attenuates the filament's affinity for the clamp. This last step initiates translocation of the new ATP-containing terminus to the clamp, whereupon another cycle begins anew. This model explains how surface-tethered filaments can grow while exerting flexural or tensile force on the motile surface. Moreover, stochastic simulations of the model reproduce the signature motions of Listeria. This elongation motor, which we term actoclampin, exploits actin's intrinsic ATPase activity to provide a simple, high-fidelity enzymatic reaction cycle for force production that does not require elongating filaments to dissociate from the motile surface. This mechanism may operate whenever actin polymerization is called upon to generate the forces that drive cell crawling or intracellular organelle motility. PMID:11806905

  16. Midwives in India: a delayed cord clamping intervention using simulation.

    PubMed

    Faucher, M A; Riley, C; Prater, L; Reddy, M P

    2016-09-01

    Iron deficiency is a prevalent health problem in India affecting women and newborns. Delayed umbilical cord clamping at birth is a safe and effective means for increasing serum iron levels in newborns up to 6 months of age. The study aim was to increase the utilization of delayed cord clamping in a group of midwives working in Hyderabad, India. A single group pre- and post-test design was used to evaluate knowledge, beliefs and practice before and after a delayed cord clamping intervention including follow-up at 10 months after the original intervention. The intervention included lectures and simulation. Results show significant increases in knowledge and positive beliefs about the practice of delayed cord clamping. Simulation was effective for eliciting important feedback related to learning. Results represent a small group of midwives working with a non-profit foundation in Southern India. Language discordancy and cultural norms in this group of midwives may have influenced results. Knowledge, beliefs and practice related to delayed cord clamping were all significantly improved after the intervention. The Knowledge to Action framework using simulation is an effective cross-cultural method for implementing education about evidence-based practice. Midwives are invested in learning practices that promote public health. Changing institutional policy may have limitations without first considering normative practice. Using simulation combined with institutional health policy appears to result in significant uptake of practice change. Qualitative studies exploring the interconnections between cultural norms and decision making may be informative about promoting practice change particularly in this setting. Upscaling midwifery has been recommended to improve maternal and child health in India. © 2016 International Council of Nurses.

  17. Polarization states and dielectric responses of elastically clamped ferroelectric nanocrystals

    NASA Astrophysics Data System (ADS)

    Azovtsev, A. V.; Pertsev, N. A.

    2016-12-01

    Polarization states and physical properties of ferroelectrics depend on the mechanical boundary conditions due to electrostrictive coupling between electric polarization and lattice strains. Here, we describe theoretically both equilibrium thermodynamic states and electric permittivities of ferroelectric nanocrystals subjected to the elastic three-dimensional (3D) clamping by a surrounding dielectric material. The problem is solved by the minimization of a special thermodynamic potential that describes the case of an ellipsoidal ferroelectric inclusion embedded into a linear elastic matrix. Numerical calculations are performed for BaTiO3, PbTiO3, and Pb(Zr0.5Ti0.5)O3 nanoparticles surrounded by silica glass. It is shown that, in the case of BaTiO3 and PbTiO3, elastic 3D clamping may change the order of a ferroelectric phase transition from first to second. Furthermore, the mechanical inclusion-matrix interaction shifts the temperatures of structural transitions between different ferroelectric states and even eliminates some ferroelectric phases existing in stress-free BaTiO3 and Pb(Zr0.5Ti0.5)O3 crystals. Another important effect of elastic clamping is the lowering of the symmetry of ferroelectric states in ellipsoidal inclusions, where orthorhombic and monoclinic phases may form instead of the tetragonal and rhombohedral bulk counterparts. Finally, our thermodynamic calculations show that the dielectric responses of studied perovskite ferroelectrics are sensitive to matrix-induced clamping as well. For instance, dielectric peaks occurring at structural transitions between different ferroelectric phases in BaTiO3 appear to be much higher in spherical inclusions than in the freestanding crystal. Predicted clamping-induced enhancement of certain dielectric responses at room temperature indicates that composite materials comprising nanocrystals of perovskite ferroelectrics are promising for device applications requiring the use of high-permittivity dielectrics.

  18. [Flexible bronchoscopy techniques: bronchoalveolar lavage, bronchial biopsy and transbronchial biopsy].

    PubMed

    Escribano Montaner, A; Moreno Galdó, A

    2005-04-01

    This article completes previous recommendations of the Techniques Group of the Spanish Society of Pediatric Pulmonologists on the practice of flexible bronchoscopy in children. We review the most frequently performed diagnostic and therapeutic procedures applied through the flexible bronchoscope: bronchoalveolar lavage, bronchial biopsy and transbronchial biopsy. Recommendations are also provided on the practice of nonbronchoscopic bronchoalveolar lavage. We review the indications and contraindications of these techniques, the equipment required, and the preparation and monitoring of the patient before, during and after the procedure. The complications of these techniques are also discussed. These recommendations may be adopted, modified or rejected according to clinical needs and constraints.

  19. Incremental value of transition zone and midline apical biopsy at baseline TRUS-guided biopsy for prostate cancer detection.

    PubMed

    Somford, D M; Vreuls, W; Jansen, T S; van Basten, J P; Vergunst, H

    2014-04-01

    To determine the diagnostic yield of transition zone (TZB) and midline apical biopsies (MAB) in baseline transrectal ultrasound (TRUS)-guided biopsies and to establish whether TZB and MAB for the diagnosis of prostate cancer (PCa) add clinical relevant information. We performed baseline 9-core TRUS-guided biopsy in 412 consecutive subjects using sextant biopsies of the PZ (PZB), with an additional TZB on either side and a MAB at the prostatic apex. We determined the incremental diagnostic value of additional TZB an MAB to sextant PZB. Within a cohort of 412 patients with a median PSA of 7.5 ng/ml, 178 (43.2 %) patients were diagnosed with PCa upon baseline TRUS-guided biopsies. In 102 cases, at least one TZB was positive for PCa, with 6/412 (1.4 %) cases displaying PCa in the TZB only. MAB alone was positive for PCa in 4/412 (1.0 %) cases. One case (1/412; 0.2 %) had only a TZB and a MAB positive for PCa without positive PZB. Thus, 11/412 (2.7 %) of cases would not have been diagnosed with PCa at baseline TRUS-guided biopsy had only sextant PZ biopsy been performed. TZB detected a high-grade Gleason component (Gleason 4 and/or 5) not present in the PZB in 2.4 % of PCa cases. There is limited value for TZB and MAB in the context of sextant PZB at baseline TRUS-guided biopsies for PCa.

  20. Vibration control of a flexible clamped-clamped plate based on an improved FULMS algorithm and laser displacement measurement

    NASA Astrophysics Data System (ADS)

    Xie, Lingbo; Qiu, Zhi-cheng; Zhang, Xian-min

    2016-06-01

    This paper presents a novel active resonant vibration control experiment of a flexible clamped-clamped plate using an improved filtered-U least mean square (FULMS) algorithm and laser displacement measurement. Different from the widely used PZT sensors or acceleration transducers, the vibration of the flexible clamped-clamped plate is measured by a non-contact laser displacement measurement sensor with higher measurement accuracy and without additional load to the plate. The conventional FULMS algorithm often uses fixed step size and needs reference signal related to the external disturbance signal. However, the fixed step size method cannot obtain a fast convergence speed and it will result in a low residual error. Thus, a variable step size method is investigated. In addition, it is difficult to extract reference signal related to the vibration source directly in the practical application. Therefore, it is practically useful that a reference signal is constructed by both the controller parameters and the vibration residual signal. The experimental results demonstrate that the improved FULMS algorithm has better vibration control effect than the proportional derivative (PD) feedback control algorithm and the fixed step-size control algorithm.

  1. Current concepts in the biopsy of musculoskeletal tumors: AAOS exhibit selection.

    PubMed

    Traina, Francesco; Errani, Costantino; Toscano, Angelo; Pungetti, Camilla; Fabbri, Daniele; Mazzotti, Antonio; Donati, Davide; Faldini, Cesare

    2015-01-21

    A musculoskeletal tumor biopsy can involve fine needle aspiration, core needle biopsy, or incisional biopsy. Controversy regarding the diagnostic yield of these biopsy techniques continues. The purpose of this article is to summarize the current concepts in the biopsy of musculoskeletal tumors. We performed a literature review of clinical articles reporting on the biopsy of bone and soft-tissue primary tumors. Clinical articles were excluded on the basis on abstract content if they represented case reports, review or opinion articles, or technique descriptions. Eighteen of the thirty-nine articles that remained were excluded because the results did not indicate the diagnostic accuracy of the various biopsy techniques. Thus, twenty-one articles with diagnostic data on the biopsy of bone and soft-tissue tumors were included in this review. Core needle biopsy appeared to be more accurate than fine needle aspiration, and incisional biopsy appeared to be more accurate than both of these techniques, but the differences did not reach significance. Incisional biopsy was more expensive than the percutaneous biopsy methods. In deep musculoskeletal tumors, incorporation of ultrasonography or computed tomography for guidance is easy and safe and can be useful for increasing the accuracy of the biopsy. Advantages of a percutaneous technique compared with an incisional one are the low risk of contamination and the minimally invasive nature. Certain anatomic locations and histologic types were associated with diagnostic difficulty. Vertebral tumors had the lowest diagnostic accuracy regardless of the biopsy technique. Myxoid, infection, and round cell histologies were associated with the lowest diagnostic accuracy. The current literature has not clarified the optimal biopsy technique for the diagnosis of bone and soft-tissue tumors. However, core needle biopsy is usually preferable to incisional biopsy because of the low risk of contamination and the low cost. In addition, the

  2. Mechanical properties and biological interaction of aortic clamps: are these all minimally invasive?

    PubMed

    Bianchi, Giacomo; Pucci, Angela; Matteucci, Marco; Varone, Egidio; Romano, Simone Lorenzo; Lionetti, Vincenzo; Glauber, Mattia

    2013-01-01

    Although specifically designed aortic clamps are mainstay of minimally invasive cardiac surgery, so far, no comparative reports about their mechanical properties and interaction with the aortic wall have been reported. In this study, the generated force in the clamps' jaws and the biological response of the aorta after clamping are evaluated. The jaw force of five commercially available clamps [Geister, Cygnet, Cardiovision (CV) 195.10, CV 195.40, and CV 195.83] was assessed by clamping a 2.2-mm compression load cell with a dedicated computer universal serial bus interface at the proximal, the middle, and the distal site from the fulcrum. Biological response of the aortic wall was assessed in five minipigs (weight, 38-40 kg) that underwent thoracic aorta clamping and leakage point test. Immunohistochemistry and morphometric analysis were carried out for each aortic segment tested. Force generation pattern is peculiar of each clamp, being higher in the proximal and the middle portion and lower in the distal part. One clamp (Cygnet) exhibited homogeneous maximal force generation at all three sites. All clamps exhibited peculiar crushing artifacts. A variable degree of endothelial layer disruption occurred in all clamping tests; three clamps (CV 195.10, Cygnet, and Geister) had the lower amount of intact endothelium. The clamping force was not associated with the degree of endothelial disruption (P value was not significant). The choice of a clamp that is not only minimally invasive in design but also least traumatic will help avoid complications of aortic manipulation.

  3. The contribution of CT-guided transthoracic lung biopsy to the diagnosis of organising pneumonia.

    PubMed

    Metzger, F; Pernet, D; Manzoni, P; Ranfaing, E; Dalphin, J-C

    2010-09-01

    Organising pneumonia is a pulmonary disease with variable clinical and radiological features and with many differential diagnoses. Diagnosis is based on histology obtained by either transbronchial or surgical lung biopsy but these techniques have several disadvantages. The aim of this study was to evaluate the diagnostic yield of CT-guided transthoracic lung biopsy in organising pneumonia and to compare it to the usual diagnostic tools. Six cases of organising pneumonia diagnosed with CT-guided lung biopsy are reported and discussed. The role of CT-guided lung biopsy in the diagnosis of organising pneumonia was also reviewed in the literature. CT-guided transthoracic lung biopsies provided a higher rate of adequate samples than transbronchial biopsies (92-100% versus 77-86%). The samples were larger, which reduced the risks of misdiagnosis and increased the diagnostic yield (88-97% versus 26-55% in pulmonary nodules and 42-100% versus 66-75% in diffuse pulmonary disease). Complications were rare and generally not serious. CT-guided transthoracic lung biopsy may be considered in place of transbronchial biopsy in the diagnosis of organising pneumonia. Surgical lung biopsy remains the gold standard method for diagnosis. Copyright © 2010 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  4. Comparison between 1-needle technique versus 2-needle technique for bone marrow aspiration and biopsy procedures.

    PubMed

    Al-Ibraheemi, Alyaa; Pham, Tiffany; Chen, Lei; Syklawer, Erica; Quesada, Andres; Wahed, Amer; Nedelcu, Elena; Nguyen, Andy N D

    2013-07-01

    Bone marrow examination is essential for diagnosis and staging of hematologic disorders. Traditionally, the bone marrow biopsy and aspirate are obtained with 2 needles at 2 separate sites. This approach is associated with significant discomfort, procedural time, and occasionally, morbidity. Although previous observations had suggested that a single-needle technique at one site is a simpler and less-painful procedure, there had been concern that the 1-needle technique may yield a suboptimal biopsy for diagnosis. To conduct a systematic comparison of multiple parameters of bone marrow biopsy specimens obtained by the traditional 2-needle technique versus the 1-needle technique for bone marrow collection. We retrospectively evaluated 20 biopsy specimens obtained by each of the 2 mentioned techniques by comparing the morphologic quality of the biopsy, biopsy length, and biopsy cellularity. We found that the 1-needle technique yielded an adequate biopsy for diagnosis. The measured parameters of the samples obtained by the 1-needle versus 2-needle techniques were similar. This study suggests that the 1-needle technique may be preferred for bone marrow aspirate and biopsy.

  5. The Utility of Endoscopic Biopsies in Patients with Normal Upper Endoscopy

    PubMed Central

    McLean, Carolyn; Gregor, James; Yan, Brian

    2016-01-01

    Background and Aims. Upper endoscopy is a valuable tool in the workup of gastrointestinal (GI) complaints. The purpose of this study is to determine cost and yield of taking biopsies in a normal upper GI tract. Methods. This is a retrospective study where all upper GI biopsies were identified between May 2012 and April 2013, at a tertiary care center. Clinical, procedural, and pathology reports were reviewed to identify patient demographics, procedure information, and pathology diagnosis. Results. Biopsies of the upper GI tract were taken in 1297 patients with normal upper endoscopies. In patients with normal upper endoscopy, 22% of esophageal, 44% of gastric, and 12% of duodenal biopsies were abnormal. The most frequent abnormality was reflux esophagitis in 16% of esophageal biopsies, chronic gastritis in 23% of gastric biopsies, and increased intraepithelial lymphocytes in 6% of duodenal biopsies. The additional cost for taking biopsies in a normal upper GI tract for a diagnosis of eosinophilic esophagitis was $2963 Canadian (CAD), H. pylori associated gastritis was $1404 CAD, and celiac disease was $3024 CAD. Conclusions. The yield of biopsy in normal upper endoscopy varied with location, but the additional expense can be costly and should be tailored to appropriate clinical situations. PMID:27478819

  6. Is ultrasonography-guided modified coaxial core biopsy of the breast a better technique?

    PubMed

    Wong, C S; Chu, Y C; Wong, K W; Yeung, T H; Ma, K F

    2009-08-01

    To compare the diagnostic rate, patient comfort, and complications of ultrasonography-guided breast biopsy using a modified coaxial technique with ultrasonography-guided fine needle aspiration and traditional core biopsy. A secondary objective was to describe the use of the coaxial technique for the biopsy of breast lesions and our initial experience. Retrospective study. A regional hospital in Hong Kong. Patients, who were referred for ultrasonography-guided fine needle aspiration or biopsy from 23 November 2007 to 19 March 2008, were divided into three groups. For breast lesions of 8 mm or smaller, fine needle aspirations were performed. For breast lesions larger than 8 mm, the patients were randomly divided into groups receiving traditional core biopsies and coaxial biopsies. The pathological reports were reviewed. Diagnostic rate, patient comfort assessed in terms of pain, and any procedural complications. A total of 45 ultrasonography-guided fine needle aspirations or biopsies of breast lesions were performed. All core biopsies using the traditional core technique (n=15) and coaxial technique (n=16) were diagnostic. While for fine needle aspirations, three (21%) of 14 were not diagnostic and repeat biopsies were undertaken for the corresponding patients. Except for one breast lesion biopsied with the coaxial technique that revealed invasive ductal carcinoma, all others yielded benign lesions. The average pain score for coaxial biopsies was 2.2, while for traditional core biopsies and fine needle aspirations, average scores were 3.7 and 3.8, respectively (P=0.022). No procedure-related complication was documented with either of the three techniques. Modified coaxial core biopsy of the breast has an optimal diagnostic rate and hence avoids the need for repeat biopsies. It is associated with better patient comfort and no increase in the risk of complications.

  7. Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors.

    PubMed

    Jung, Yoon Suk; Lee, Hyuk; Kim, Kyungeun; Sohn, Jin Hee; Kim, Hong Joo; Park, Jung Ho

    2016-11-01

    The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730).

  8. Using Forceps Biopsy after Small Submucosal Dissection in the Diagnosis of Gastric Subepithelial Tumors

    PubMed Central

    2016-01-01

    The current tissue sampling techniques for subepithelial tumors (SETs) of the gastrointestinal (GI) tract have limited diagnostic efficacy. We evaluated the diagnostic yield and safety of forceps biopsies after small endoscopic submucosal dissection (SESD biopsies) in the diagnosis of gastric SETs. A total of 42 patients with gastric SETs > 10 mm were prospectively enrolled between May 2013 and October 2014. A dual knife was used to incise the mucosa and submucosa and forceps biopsies were then introduced deep into the lesion. To compare SESD biopsies with EUS-FNA, we used the retrospective data of 30 EUS-FNA cases. The diagnostic yield of SESD biopsies was comparable to that of EUS-FNA (35/42, 83.3% vs. 24/30, 80.0%, P = 0.717). The mean procedure time of SESD biopsies was shorter than that of EUS-FNA (10 vs. 37 minutes, P < 0.001). There were no procedure-related adverse events in the both group. The pathological diagnoses in SESD biopsies group included 15 leiomyomas, 7 GISTs, 10 heterotopic pancreases, 2 lipomas, and one other lesion. SESD biopsies are an easy, effective and safe technique for the diagnosis of gastric SETs and its diagnostic yield is comparable to that of EUS-FNA. This technique may be a reliable alternative to conventional EUS-FNA (Clinical trial registration No. KCT0000730). PMID:27709855

  9. Toward 3D-guided prostate biopsy target optimization: an estimation of tumor sampling probabilities

    NASA Astrophysics Data System (ADS)

    Martin, Peter R.; Cool, Derek W.; Romagnoli, Cesare; Fenster, Aaron; Ward, Aaron D.

    2014-03-01

    Magnetic resonance imaging (MRI)-targeted, 3D transrectal ultrasound (TRUS)-guided "fusion" prostate biopsy aims to reduce the ~23% false negative rate of clinical 2D TRUS-guided sextant biopsy. Although it has been reported to double the positive yield, MRI-targeted biopsy still yields false negatives. Therefore, we propose optimization of biopsy targeting to meet the clinician's desired tumor sampling probability, optimizing needle targets within each tumor and accounting for uncertainties due to guidance system errors, image registration errors, and irregular tumor shapes. We obtained multiparametric MRI and 3D TRUS images from 49 patients. A radiologist and radiology resident contoured 81 suspicious regions, yielding 3D surfaces that were registered to 3D TRUS. We estimated the probability, P, of obtaining a tumor sample with a single biopsy. Given an RMS needle delivery error of 3.5 mm for a contemporary fusion biopsy system, P >= 95% for 21 out of 81 tumors when the point of optimal sampling probability was targeted. Therefore, more than one biopsy core must be taken from 74% of the tumors to achieve P >= 95% for a biopsy system with an error of 3.5 mm. Our experiments indicated that the effect of error along the needle axis on the percentage of core involvement (and thus the measured tumor burden) was mitigated by the 18 mm core length.

  10. Oral biopsy: oral pathologist's perspective.

    PubMed

    Kumaraswamy, K L; Vidhya, M; Rao, Prasanna Kumar; Mukunda, Archana

    2012-01-01

    Many oral lesions may need to be diagnosed by removing a sample of tissue from the oral cavity. Biopsy is widely used in the medical field, but the practice is not quite widespread in dental practice. As oral pathologists, we have found many artifacts in the tissue specimen because of poor biopsy technique or handling, which has led to diagnostic pitfalls and misery to both the patient and the clinician. This article aims at alerting the clinicians about the clinical faults arising preoperatively, intraoperatively and postoperatively while dealing with oral biopsy that may affect the histological assessment of the tissue and, therefore, the diagnosis. It also reviews the different techniques, precautions and special considerations necessary for specific lesions.

  11. [Aspiration biopsy of the pancreas].

    PubMed

    Pérez Catzín, F; Gutiérrez Samperio, C; Valenzuela Tamariz, J

    1979-01-01

    Biopsy of the pancreas frequently is followed by complications, this is why the transoperative aspiration biopsy has been recomended. During the last 2 years we used this procedure in 46 patients; in each case, one or several aspirations were done in the more-representative area of the pancreatic pathology. With the aspirated material a smear was fixed and treated with H-E stain. Biopsy was negative for carcinoma in 30 patients (65.2%), positive in 12 (26.0%), insuficient material results in other 4 (8.6%) we consider that the procedure was useful in the 82.6% of the cases and help to elect more adecuate surgical tecnic. There were no complications and we concluded that this is not a harmful procedure. The correct interpretation of the citology depends on the experience of the pathologyst with this method, to increase the percentage of correct diagnosis.

  12. Utility of abdominal skin plus subcutaneous fat and rectal mucosal biopsy in the diagnosis of AL amyloidosis with renal involvement.

    PubMed

    Li, Ting; Huang, Xianghua; Cheng, Shuiqin; Zhao, Liang; Ren, Guisheng; Chen, Wencui; Wang, Qingwen; Zeng, Caihong; Liu, Zhihong

    2017-01-01

    Skin fat biopsy of the abdominal wall is a simple and safe method for detecting amyloidosis, and rectal mucosal biopsy is also frequently used for screening for the disease; however, the sensitivity of these approaches has not been fully studied. The aim of this study was to evaluate the efficacy of skin fat biopsy combined with rectal mucosal biopsy as a screening procedure for the diagnosis of systemic immunoglobulin light-chain (AL) amyloidosis. We retrospectively analyzed 224 AL amyloidosis patients confirmed by renal biopsy, including a test group of 165 patients and validation group of 59 patients. Surgical skin fat biopsy from the abdominal wall and rectal mucosal biopsy under endoscopy was performed to obtain specimens. Congo red staining and immunofluorescence staining with antibodies against light chains were performed to type the disease. Pathology reports were reviewed to assess the diagnostic sensitivity of skin fat biopsy and rectal mucosal biopsy. Diagnostic specificity was not examined in the present study, because no healthy volunteers and only few patients with other diseases had performed immunofluorescence staining on skin fat and rectal specimens. Of the 165 patients in the test group, Congo red staining of skin fat and rectal mucosal specimens was associated with a sensitivity of 89.3% and 94.8%, respectively. The sensitivity increased to 98.9% by combining both biopsy methods. Immunofluorescence stains were positive in 81.1% of patients undergoing skin fat biopsy and 84.7% of patients undergoing rectal mucosal biopsy. Immunofluorescence stains yielded positive results in 86.7% of cases combining skin fat biopsy with rectal mucosal biopsy. The diagnostic results also performed well in the validation group. Surgical skin biopsy including the subcutaneous fat pad can be performed safely at the bedside and is useful for diagnosing AL amyloidosis. Combining skin fat biopsy with rectal mucosal biopsy may identify amyloid deposits in almost all

  13. A Molecular Imaging Approach to Mercury Sensing Based on Hyperpolarized (129)Xe Molecular Clamp Probe.

    PubMed

    Guo, Qianni; Zeng, Qingbin; Jiang, Weiping; Zhang, Xiaoxiao; Luo, Qing; Zhang, Xu; Bouchard, Louis-S; Liu, Maili; Zhou, Xin

    2016-03-14

    Mercury pollution, in the form of mercury ions (Hg(2+)), is a major health and environmental hazard. Commonly used sensors are invasive and limited to point measurements. Fluorescence-based sensors do not provide depth resolution needed to image spatial distributions. Herein we report a novel sensor capable of yielding spatial distributions by MRI using hyperpolarized (129)Xe. A molecular clamp probe was developed consisting of dipyrrolylquinoxaline (DPQ) derivatives and twocryptophane-A cages. The DPQ derivatives act as cation receptors whereas cryptophane-A acts as a suitable host molecule for xenon. When the DPQ moiety interacts with mercury ions, the molecular clamp closes on the ion. Due to overlap of the electron clouds of the two cryptophane-A cages, the shielding effect on the encapsulated Xe becomes important. This leads to an upfield change of the chemical shift of the encapsulated Xe. This sensor exhibits good selectivity and sensitivity toward the mercury ion. This mercury-activated hyperpolarized (129)Xe-based chemosensor is a new concept method for monitoring Hg(2+) ion distributions by MRI.

  14. Testing of Diode-Clamping in an Inductive Pulsed Plasma Thruster Circuit

    NASA Technical Reports Server (NTRS)

    Toftul, Alexandra; Polzin, Kurt A.; Martin, Adam K.; Hudgins, Jerry L.

    2014-01-01

    Testing of a 5.5 kV silicon (Si) diode and 5.8 kV prototype silicon carbide (SiC) diode in an inductive pulsed plasma thruster (IPPT) circuit was performed to obtain a comparison of the resulting circuit recapture efficiency,eta(sub r), defined as the percentage of the initial charge energy remaining on the capacitor bank after the diode interrupts the current. The diode was placed in a pulsed circuit in series with a silicon controlled rectifier (SCR) switch, and the voltages across different components and current waveforms were collected over a range of capacitor charge voltages. Reverse recovery parameters, including turn-off time and peak reverse recovery current, were measured and capacitor voltage waveforms were used to determine the recapture efficiency for each case. The Si fast recovery diode in the circuit was shown to yield a recapture efficiency of up to 20% for the conditions tested, while the SiC diode further increased recapture efficiency to nearly 30%. The data presented show that fast recovery diodes operate on a timescale that permits them to clamp the discharge quickly after the first half cycle, supporting the idea that diode-clamping in IPPT circuit reduces energy dissipation that occurs after the first half cycle

  15. Automated and manual patch clamp data of human induced pluripotent stem cell-derived dopaminergic neurons

    PubMed Central

    Franz, Denise; Olsen, Hervør Lykke; Klink, Oliver; Gimsa, Jan

    2017-01-01

    Human induced pluripotent stem cells can be differentiated into dopaminergic neurons (Dopa.4U). Dopa.4U neurons expressed voltage-gated NaV and KV channels and showed neuron-like spontaneous electrical activity. In automated patch clamp measurements with suspended Dopa.4U neurons, delayed rectifier K+ current (delayed KV) and rapidly inactivating A-type K+ current (fast KV) were identified. Examination of the fast KV current with inhibitors yielded IC50 values of 0.4 mM (4-aminopyridine) and 0.1 mM (tetraethylammonium). In manual patch clamp measurements with adherent Dopa.4U neurons, fast KV current could not be detected, while the delayed KV current showed an IC50 of 2 mM for 4-aminopyridine. The NaV channels in adherent and suspended Dopa.4U neurons showed IC50 values for tetrodotoxin of 27 and 2.9 nM, respectively. GABA-induced currents that could be observed in adherent Dopa.4U neurons could not be detected in suspended cells. Application of current pulses induced action potentials in approx. 70 % of the cells. Our results proved the feasibility of automated electrophysiological characterization of neuronal cells. PMID:28440808

  16. Magnetic Resonance and Ultrasound Image Fusion Supported Transperineal Prostate Biopsy Using the Ginsburg Protocol: Technique, Learning Points, and Biopsy Results.

    PubMed

    Hansen, Nienke; Patruno, Giulio; Wadhwa, Karan; Gaziev, Gabriele; Miano, Roberto; Barrett, Tristan; Gnanapragasam, Vincent; Doble, Andrew; Warren, Anne; Bratt, Ola; Kastner, Christof

    2016-08-01

    Prostate biopsy supported by transperineal image fusion has recently been developed as a new method to the improve accuracy of prostate cancer detection. To describe the Ginsburg protocol for transperineal prostate biopsy supported by multiparametric magnetic resonance imaging (mpMRI) and transrectal ultrasound (TRUS) image fusion, provide learning points for its application, and report biopsy results. The article is supplemented by a Surgery in Motion video. This single-centre retrospective outcome study included 534 patients from March 2012 to October 2015. A total of 107 had no previous prostate biopsy, 295 had benign TRUS-guided biopsies, and 159 were on active surveillance for low-risk cancer. A Likert scale reported mpMRI for suspicion of cancer from 1 (no suspicion) to 5 (cancer highly likely). Transperineal biopsies were obtained under general anaesthesia using BiopSee fusion software (Medcom, Darmstadt, Germany). All patients had systematic biopsies, two cores from each of 12 anatomic sectors. Likert 3-5 lesions were targeted with a further two cores per lesion. Any cancer and Gleason score 7-10 cancer on biopsy were noted. Descriptive statistics and positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. The detection rate of Gleason score 7-10 cancer was similar across clinical groups. Likert scale 3-5 MRI lesions were reported in 378 (71%) of the patients. Cancer was detected in 249 (66%) and Gleason score 7-10 cancer was noted in 157 (42%) of these patients. PPV for detecting 7-10 cancer was 0.15 for Likert score 3, 0.43 for score 4, and 0.63 for score 5. NPV of Likert 1-2 findings was 0.87 for Gleason score 7-10 and 0.97 for Gleason score ≥4+3=7 cancer. Limitations include lack of data on complications. Transperineal prostate biopsy supported by MRI/TRUS image fusion using the Ginsburg protocol yielded high detection rates of Gleason score 7-10 cancer. Because the NPV for excluding Gleason score 7-10 cancer was very

  17. US-guided biopsy of neck masses in postoperative management of patients with thyroid cancer.

    PubMed

    Sutton, R T; Reading, C C; Charboneau, J W; James, E M; Grant, C S; Hay, I D

    1988-09-01

    High-frequency (10-MHz) sonography demonstrated a cervical mass or lymphadenopathy, or both, during postoperative follow-up of 52 patients who had undergone surgery for thyroid cancer. Percutaneous biopsy with ultrasonographic (US) guidance was performed in all 52 masses, 44 of which were nonpalpable. Malignant cells were obtained in 29 biopsies, and the results of 20 biopsies were negative, yielding benign lymphocytes only. Results in three biopsies were nondiagnostic due to hypocellular specimens. Therefore, 94% of biopsy results (49) of 52) were confidently assigned as either positive (56%) or negative (38%) for malignancy. There were no complications. High-frequency sonography can demonstrate clinically occult thyroid bed tumor recurrence and lymph node metastases. US-guided biopsy is an accurate and safe technique to confirm or exclude malignancy in patients at high risk of recurrence of thyroid cancer.

  18. Update on Renal Mass Biopsy.

    PubMed

    Haifler, Miki; Kutikov, Alexander

    2017-04-01

    Renal masses are diagnosed with an increasing frequency. However, a significant proportion of these masses are benign, and the majority of malignant tumors are biologically indolent. Furthermore, renal tumors are often harbored by the elderly and comorbid patients. As such, matching of renal tumor biology to appropriate treatment intensity is an urgent clinical need. Renal mass biopsy is currently a very useful clinical tool that can assist with critical clinical decision-making in patients with renal mass. Yet, renal mass biopsy is associated with limitations and, as such, may not be appropriate for all patients.

  19. Distinct roles for ATP binding and hydrolysis at individual subunits of an archaeal clamp loader

    PubMed Central

    Seybert, Anja; Wigley, Dale B

    2004-01-01

    Circular clamps are utilised by replicative polymerases to enhance processivity. The topological problem of loading a toroidal clamp onto DNA is overcome by ATP-dependent clamp loader complexes. Different organisms use related protein machines to load clamps, but the mechanisms by which they utilise ATP are surprisingly different. Using mutant clamp loaders that are deficient in either ATP binding or hydrolysis in different subunits, we show how the different subunits of an archaeal clamp loader use ATP binding and hydrolysis in distinct ways at different steps in the loading process. Binding of nucleotide by the large subunit and three of the four small subunits is sufficient for clamp loading. However, ATP hydrolysis by the small subunits is required for release of PCNA to allow formation of the complex between PCNA and the polymerase, while hydrolysis by the large subunit is required for catalytic clamp loading. PMID:15014449

  20. Timing of umbilical cord clamping: effect on iron endowment of the newborn and later iron status.

    PubMed

    Chaparro, Camila M

    2011-11-01

    The optimal timing of umbilical cord clamping has been debated in the scientific literature for at least the last century, when cord clamping practices shifted from delayed towards immediate clamping. Recent research provides evidence for the beneficial effect of delayed cord clamping on infant iron status. The present review describes the physiological basis for the impact of cord clamping time on total body iron at birth and the relationship between birth body iron, as affected by cord clamping time, and iron status later in infancy. This research is discussed in the context of current clamping practices, which tend towards early cord clamping in most settings, as well as the high levels of anemia present in young infants in many countries worldwide. © 2011 International Life Sciences Institute.

  1. Trans-rectal interventional MRI: initial prostate biopsy experience

    NASA Astrophysics Data System (ADS)

    Greenwood, Bernadette M.; Behluli, Meliha R.; Feller, John F.; May, Stuart T.; Princenthal, Robert; Winkel, Alex; Kaminsky, David B.

    2010-02-01

    Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the prostate gland when evaluated along with T2-weighted images, diffusion-weighted images (DWI) and their corresponding apparent diffusion coefficient (ADC) maps can yield valuable information in patients with rising or elevated serum prostate-specific antigen (PSA) levels1. In some cases, patients present with multiple negative trans-rectal ultrasound (TRUS) biopsies, often placing the patient into a cycle of active surveillance. Recently, more patients are undergoing TRIM for targeted biopsy of suspicious findings with a cancer yield of ~59% compared to 15% for second TRUS biopsy2 to solve this diagnostic dilemma and plan treatment. Patients were imaged in two separate sessions on a 1.5T magnet using a cardiac phased array parallel imaging coil. Automated CAD software was used to identify areas of wash-out. If a suspicious finding was identified on all sequences it was followed by a second imaging session. Under MRI-guidance, cores were acquired from each target region3. In one case the microscopic diagnosis was prostatic intraepithelial neoplasia (PIN), in the other it was invasive adenocarcinoma. Patient 1 had two negative TRUS biopsies and a PSA level of 9ng/mL. Patient 2 had a PSA of 7.2ng/mL. He underwent TRUS biopsy which was negative for malignancy. He was able to go on to treatment for his prostate carcinoma (PCa)4. MRI may have an important role in a subset of patients with multiple negative TRUS biopsies and elevated or rising PSA.

  2. A High-Efficiency Diode-Clamped Linear Amplifier

    NASA Astrophysics Data System (ADS)

    Fujita, Hideaki

    This paper proposes a new power converter without any switching operation, which works as a linear amplifier. The main circuit of the proposed converter consists of series-connected MOSFETs, series-multi dc power supplies and clamping diodes. The circuit configuration is similar to a diode-clamped multi-level inverter, except for using complementary power devices, which are n- and p-channel MOSFETs. One of the series-connected MOSFETs operates in an active state just like a linear amplifier, while the other MOSFETs operate in on or off states like an inverter circuit. As a result, the proposed converter achieves an acceptable efficiency as high as 90% without any ripples nor harmonics caused by switching operation. Experimental results demonstrate that the proposed converter has capability of driving a 2.2-kW three-phase induction motor.

  3. Patch-clamp experiments under micro-gravity.

    PubMed

    Meissner, Klaus; Hanke, Wolfgang

    2002-07-01

    For human based space research it is of high importance to understand the influence of gravity on the properties of single ion channels in biological membranes, as these are involved in about all biological processes. The patch clamp technique is the best established method to investigate electrophysiological properties of single ion channels in detail. Consequently, a patch clamp set-up was designed for the drop tower in Bremen, Germany. Using this set-up among others, successfully leech neurons have been patched under micro-gravity, delivering data about ion channel behaviour, which were compared to results from bilayer experiments in the drop tower and to results from lab controls under 1 g and under higher gravity.

  4. Active energy recovery clamping circuit to improve the performance of power converters

    DOEpatents

    Whitaker, Bret; Barkley, Adam

    2017-05-09

    A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

  5. Magnetic Resonance Imaging-Ultrasound Fusion Biopsy During Prostate Cancer Active Surveillance.

    PubMed

    Tran, Geraldine N; Leapman, Michael S; Nguyen, Hao G; Cowan, Janet E; Shinohara, Katsuto; Westphalen, Antonio C; Carroll, Peter R

    2017-08-01

    Fusion biopsy using multiparametric magnetic resonance imaging (MRI) and transrectal ultrasound has demonstrated favorable detection rates of high-grade prostate cancer (PCa) among previously undiagnosed men. However, the diagnostic yield among men with active surveillance (AS) remains undefined. To determine the utility of MRI-ultrasound fusion biopsy during AS by reporting rates of PCa upgrading and comparing findings with systematic biopsy. We identified patients with low- and intermediate-risk PCa enrolled in AS who received MRI-ultrasound fusion surveillance biopsies. All completed prostate multiparametric MRI with 3-T and endorectal coil reviewed by radiologists selecting regions of interest, and all underwent MRI-ultrasound fusion biopsy with concurrent systematic biopsy. We report MRI-ultrasound fusion biopsy findings, rates of Gleason score (GS) upgrading to ≥3 + 4 (any upgrading) and to ≥4 + 3 (major upgrading), tumor involvement estimates using descriptive statistics, McNemar's test of symmetry, and multivariate logistic regression. Overall, 207 men underwent MRI-ultrasound fusion biopsy following radiologic suspicion on multiparametric MRI and met inclusion criteria. Agreement between systematic and MRI-ultrasound fusion biopsy GS was borderline statistically significant (p<0.047). In total, 83 men (40%) experienced any upgrading, including 49 (24%) on systematic sampling, 30 (14%) on MRI-targeted cores, and four (2%) on both. Among those with negative results on MRI-ultrasound fusion biopsy, seven (9%) exhibited major upgrading with systematic biopsy. MRI suspicion scores were high (4/5) for all but two patients with any upgrading and for all who experienced major upgrading. On multivariate analysis, older age was associated with higher odds of any upgrading for men with GS ≤3 + 3 on previous biopsy (odds ratio: 1.10; 95% confidence interval, 1.01-1.20; p=0.03). MRI-ultrasound fusion biopsy resulted in upgrading otherwise undetected by systematic

  6. Vacuum Enhanced Cutaneous Biopsy Instrument

    SciTech Connect

    Collins, Joseph

    1999-06-25

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  7. Vacuum enhanced cutaneous biopsy instrument

    DOEpatents

    Collins, Joseph

    2000-01-01

    A syringe-like disposable cutaneous biopsy instrument equipped with a tubular blade at its lower end, and designed so that a vacuum is created during use, said vacuum serving to retain undeformed a plug of tissue cut from a patient's skin.

  8. Biopsy techniques for intraocular tumors

    PubMed Central

    Rishi, Pukhraj; Dhami, Abhinav; Biswas, Jyotirmay

    2016-01-01

    Biopsy involves the surgical removal of a tissue specimen for histopathologic evaluation. Most intraocular tumors are reliably diagnosed based on the clinical evaluation or with noninvasive diagnostic techniques. However, accurately diagnosing a small percentage of tumors can be challenging. A tissue biopsy is thus needed to establish a definitive diagnosis and plan the requisite treatment. From fine-needle aspiration biopsy (FNAB) to surgical excision, all tissue collection techniques have been studied in the literature. Each technique has its indications and limitations. FNAB has been reported to provide for 88–95% reliable and safe ophthalmic tumor diagnosis and has gained popularity for prognostic purposes and providing eye conserving treatment surgeries. The technique and instrumentation for biopsy vary depending upon the tissue involved (retina, choroid, subretinal space, vitreous, and aqueous), suspected diagnosis, size, location, associated retinal detachment, and clarity of the media. The cytopathologist confers a very important role in diagnosis and their assistance plays a key role in managing and planning the treatment for malignancies. PMID:27488148

  9. Cleaning patch-clamp pipettes for immediate reuse

    PubMed Central

    Kolb, I.; Stoy, W. A.; Rousseau, E. B.; Moody, O. A.; Jenkins, A.; Forest, C. R.

    2016-01-01

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator. PMID:27725751

  10. A mathematical model of the euglycemic hyperinsulinemic clamp

    PubMed Central

    Picchini, Umberto; De Gaetano, Andrea; Panunzi, Simona; Ditlevsen, Susanne; Mingrone, Geltrude

    2005-01-01

    Background The Euglycemic Hyperinsulinemic Clamp (EHC) is the most widely used experimental procedure for the determination of insulin sensitivity, and in its usual form the patient is followed under insulinization for two hours. In the present study, sixteen subjects with BMI between 18.5 and 63.6 kg/m2 were studied by long-duration (five hours) EHC. Results From the results of this series and from similar reports in the literature it is clear that, in obese subjects, glucose uptake rates continue to increase if the clamp procedure is prolonged beyond the customary 2 hours. A mathematical model of the EHC, incorporating delays, was fitted to the recorded data, and the insulin resistance behaviour of obese subjects was assessed analytically. Obese subjects had significantly less effective suppression of hepatic glucose output and higher pancreatic insulin secretion than lean subjects. Tissue insulin resistance appeared to be higher in the obese group, but this difference did not reach statistical significance. Conclusion The use of a mathematical model allows a greater amount of information to be recovered from clamp data, making it easier to understand the components of insulin resistance in obese vs. normal subjects. PMID:16269082

  11. Cleaning patch-clamp pipettes for immediate reuse.

    PubMed

    Kolb, I; Stoy, W A; Rousseau, E B; Moody, O A; Jenkins, A; Forest, C R

    2016-10-11

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator.

  12. Force-clamp laser trapping of rapidly interacting molecules

    NASA Astrophysics Data System (ADS)

    Capitanio, Marco; Monico, Carina; Vanzi, Francesco; Pavone, Francesco S.

    2013-06-01

    Forces play a fundamental role in a wide array of biological processes, regulating enzymatic activity, kinetics of molecular bonds, and molecular motors mechanics. Single molecule force spectroscopy techniques have enabled the investigation of such processes, but they are inadequate to probe short-lived (millisecond and sub-millisecond) molecular complexes. We developed an ultrafast force-clamp spectroscopy technique that uses a dual trap configuration to apply constant loads to a single intermittently interacting biological polymer and a binding protein. Our system displays a delay of only ˜10 μs between formation of the molecular bond and application of the force and is capable of detecting interactions as short as 100 μs. The force-clamp configuration in which our assay operates allows direct measurements of load-dependence of lifetimes of single molecular bonds. Moreover, conformational changes of single proteins and molecular motors can be recorded with sub-nanometer accuracy and few tens of microseconds of temporal resolution. We demonstrate our technique on molecular motors, using myosin II from fast skeletal muscle and on protein-DNA interaction, specifically on Lactose repressor (LacI). The apparatus is stabilized to less than 1 nm with both passive and active stabilization, allowing resolving specific binding regions along the actin filament and DNA molecule. Our technique extends single-molecule force-clamp spectroscopy to molecular complexes that have been inaccessible up to now, opening new perspectives for the investigation of the effects of forces on biological processes.

  13. DNA Sliding Clamps: Just the Right Twist to Load onto DNA

    SciTech Connect

    Barsky, D; Venclovas, C

    2005-10-24

    Two recent papers illuminate a long sought step in DNA sliding clamp loading. One paper reveals the structure of the PCNA clamp wrapped around DNA--still open from being loaded--while a second paper discovers that the clamp may assist this process by forming a right-handed helix upon opening.

  14. Pressure controlled clamp using shape memory alloy for minimal vessel invasion in blood flow occlusion.

    PubMed

    Zhang, Ye; Kanetaka, Hiroyasu; Sano, Yuya; Kano, Mitsuhiro; Kudo, Tadaaki; Sato, Takumi; Shimizu, Yoshinaka

    2013-01-01

    Vessel damage after clamping may affect the success of surgical operations. A new pressure controlled clamp (SMA clamp) was designed using super elastic property of shape memory alloy (SMA) to realize atraumatic vessel occlusion. The ability and biological effect of the SMA clamp to control pressure was investigated in vivo. The loading-displacement curves of the SMA clamps (experimental group) and conventional clamp (control group) by occlusion of pig carotid arteries were evaluated using a clamping-pressure analyzing system. To investigate macroscopically and histologically the vessel damage of the SMA and conventional clamps, pig carotid arteries were stained with Evan's blue and its histological sections were stained with Elastica Massion after clamping for fifteen minutes. Constant value was shown in the loading-displacement curve of SMA clamp. In the control group, damaged area stained with Evan's blue in the vessel wall showed enlargement with the pressure increasing. Less areas in experimental groups are observed than that in the control group. Histological section in the experimental group showed no obvious except a slight compressive damage in the tunica intima. In the control group, vessel wall showed irreversible damages. This experiment indicated that the SMA clamp, which has a unique mechanical property, can be used without vessels damage. This pressure controlled clamp can be a selection in clinical apparatus to improve surgical safety.

  15. Intra-patient comparison of parietal pleural biopsies by rigid forceps, flexible forceps and cryoprobe obtained during medical thoracoscopy: a prospective series of 80 cases with pleural effusion.

    PubMed

    Wurps, H; Schönfeld, N; Bauer, T T; Bock, M; Duve, C; Sauer, R; Mairinger, T; Griff, S

    2016-07-07

    There is only few data available on the use of cryotechnique during medical thoracoscopy. Medical thoracoscopy was performed in consecutive patients with pleural effusion. Prospectively, biopsies were taken by rigid forceps, flexible forceps and cryoprobe. Specimen size, depth and diagnostic yield were compared. 80 Patients were included. 408 biopsies were taken (205 rigid biopsies, 104 flexible biopsies, 99 cryobiopsies). Mean surface area of rigid biopsies was 22.6 ± 20.4 mm(2) (flexible biopsies: 7.1 ± 9.3 mm(2), cryobiopsies: 14.4 ± 12.8 mm(2)). Rigid biopsies were significantly larger than cryobiopsies (p < 0.001) and flexible biopsies (p < 0.001), crybiopsies were significantly larger than flexible biopsies (p < 0.01). A deep biopsy containing fatty tissue was harvested in 63 % of rigid biopsies (cryobiopsy: 49.5 % flexible biopsy: 39.5 %). In 79/80 cases (98.7 % 95 % CI cannot be calculated) a diagnosis was obtained by rigid biopsy (cryobiopsy: 73/80 cases (91.3 % 95 % CI 86.0 - 96.5 %), flexible biopsy: 74/80 cases (92.5 % 95 % CI 88.6 - 97.4 %)). Diagnostic yield achieved with cryobiopsies was inferior to the yield of rigid biopsies (Difference: 12.7 %), but non-inferior to flexible biopsies (Difference: 6.5 %). Cryobiopsies in medical thoracoscopy are safe with high diagnostic yield, non-inferior to flexible biopsies with increased tissue quantity and quality. Cryotechnique can develop an important role in medical thoracoscopy in the near future when rigid thoracoscopy is not available.

  16. Global optimisation methods for poroelastic material characterisation using a clamped sample in a Kundt tube setup

    NASA Astrophysics Data System (ADS)

    Vanhuyse, Johan; Deckers, Elke; Jonckheere, Stijn; Pluymers, Bert; Desmet, Wim

    2016-02-01

    The Biot theory is commonly used for the simulation of the vibro-acoustic behaviour of poroelastic materials. However, it relies on a number of material parameters. These can be hard to characterize and require dedicated measurement setups, yielding a time-consuming and costly characterisation. This paper presents a characterisation method which is able to identify all material parameters using only an impedance tube. The method relies on the assumption that the sample is clamped within the tube, that the shear wave is excited and that the acoustic field is no longer one-dimensional. This paper numerically shows the potential of the developed method. It therefore performs a sensitivity analysis of the quantification parameters, i.e. reflection coefficients and relative pressures, and a parameter estimation using global optimisation methods. A 3-step procedure is developed and validated. It is shown that even in the presence of numerically simulated noise this procedure leads to a robust parameter estimation.

  17. A randomised study on the efficacy and safety of an automated Tru-Cut needle for percutaneous liver biopsy.

    PubMed

    de Man, R A; van Buuren, H R; Hop, W C J

    2004-12-01

    We studied whether the theoretical advantages of a spring-loaded liver biopsy needle exist in clinical practice and if so if they are dependent upon the experience of the physician performing the biopsy. In a stratified randomised study we enrolled 215 consecutive patients to compare the safety and efficacy of a new automatic biopsy gun (Acecut) with that of a standard Tru-Cut needle. A total of 464 biopsies were performed. The endpoints of the study were number of needle passes needed per patient, tissue yield of each needle pass and post-biopsy complications. The performance of the automatic needle was superior and more consistent with respect to tissue yield compared with the Tru-Cut needle (median yield 100% and 80%, respectively; p < 0.001). The difference was most marked for inexperienced physicians. There was no difference between the two needles in the number of passes needed. More post-biopsy pain and post-biopsy use of analgesics were observed in the automatic needle group (p = 0.04). The automatic Tru-Cut needle offers an advantage, particularly for physicians with no or limited experience in liver biopsies. However more post-biopsy pain and post-biopsy use of analgesics were observed in the automatic needle group.

  18. Planar silicon patch-clamp electrodes integrated with polydimethylsiloxane microfluidics

    NASA Astrophysics Data System (ADS)

    Nagarah, John Michael

    The patch-clamp technique allows one to probe single ion channels and macroscopic ion channel activity in their native environment and resolve their activity as their physical and chemical surroundings are varied. The traditional method of patch-clamping cells involves bringing a clean, flame-polished glass pipette tip with a 1-2 mum diameter pore into contact with a cell membrane to form a high electrical resistance seal. This technique is the gold standard for cellular electrophysiology investigations because it allows the observation of single ion channel protein dynamics as well as activity from an ensemble ion channels from a single cell. Furthermore, any drug approved by federal drug agencies must be screened against particular ion channels with the patch-clamp technique. However, this technique by its nature is serial, time consuming, difficult when exchanging pipette solutions, and difficult to integrate with other technologies. These reasons have prompted several investigators to explore alternative approaches to traditional pipette patch-clamping to increase the throughput of measurements. Herein, I describe the development of a silicon-wafer based device platform that enables the measurement of ion channel activities. The electrical nature of the cell/wafer seal is characterized for several pore design variations. The majority of gigaohm seals obtained falls in the range of 10-20GO. The cell-attached and whole cell configurations are demonstrated. Whole cell ion channel activity originating from various cell fines is consistent with the more traditional micropipette patch-clamp recordings. The silicon fabrication methods developed, although novel, utilize established semiconductor technologies, making them amenable to batch fabrication techniques. I integrate these silicon devices with PDMS microfluidics with monolithic valves, allowing ultra-fast solution exchange as low as tens of milliseconds for the extracellular solution. Furthermore, I developed a

  19. Use and abuse of lung biopsy.

    PubMed

    Gal, Anthony A

    2005-07-01

    The lung biopsy is widely recognized as a valuable tool for the diagnosis and management of diverse pulmonary disorders. The transbronchial lung biopsy, open lung biopsy, and video assisted thoracoscopic surgery biopsy are the principal tools that have been developed for obtaining lung tissue for histopathological examination. Whereas these various types of lung biopsies are highly sensitive and specific tests available for diagnosis, they may be fraught with potential problems. This review hopes to inform the reader of the indications and limitations of the lung biopsy.

  20. Effect of Delayed Cord Clamping on Systemic Blood Flow: A Randomized Controlled Trial.

    PubMed

    Popat, Himanshu; Robledo, Kristy P; Sebastian, Lucille; Evans, Nicholas; Gill, Andrew; Kluckow, Martin; Sinhal, Sanjay; de Waal, Koert; Tarnow-Mordi, William; Osborn, David

    2016-11-01

    To determine whether delayed cord clamping improves systemic blood flow compared with immediate cord clamping in very preterm infants in the first 24 hours. Women delivering at <30 weeks' gestation at 5 tertiary centers were randomized to receive immediate cord clamping (<10 seconds) or delayed cord clamping (≥60 seconds). Echocardiography and cardiorespiratory data were collected at 3, 9, and 24 hours after birth. The primary outcome was mean lowest superior vena cava (SVC) flow. Of 266 infants enrolled, 133 were randomized to immediate cord clamping and 133 to delayed cord clamping. The 2 groups were similar at baseline, including mean gestation (immediate cord clamping 28 weeks vs delayed cord clamping 28 weeks) and birth weight (immediate cord clamping 1003 g vs delayed cord clamping 1044 g). There was no significant difference between groups in the primary outcome of mean lowest SVC flow (immediate cord clamping 71.4 mL/kg/min [SD 28.1] vs delayed cord clamping 70.2 mL/kg/min [SD 26.9]; P = .7). For secondary outcomes, hemoglobin increased by 0.9 g/dL at 6 hours in the group with delayed cord clamping (95% CI 3.9, 14.4; P = .0005, adjusted for baseline). The group with delayed cord clamping had lower right ventricular output (-21.9 mL/kg/min, 95% CI -39.0, -4.7; P = .01). Rates of treated hypotension, ductus arteriosus size and shunt direction, and treatment of the ductus arteriosus were similar. Delayed cord clamping had no effect on systemic blood flow measured as mean lowest SVC flow in the first 24 hours in infants <30 weeks' gestation. Australia New Zealand Clinical Trials Registry: ACTRN12610000633088. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Extracellular potassium accumulation in voltage-clamped frog ventricular muscle.

    PubMed Central

    Cleemann, L; Morad, M

    1979-01-01

    1. Application of voltage clamp pulses (1--10 sec) to frog ventricular strips causes temporary changes in the extracellular K concentration. 2. The changes in the extracellular K concentration can be estimated from (a) slowly decaying post-clamp after-potentials, (b) changes in the action potential duration, and (c) measurements with a K-selective micro-electrode. 3. The depolarization of the resting potential and the shortening of the action potential are present in approximately the same proportions during voltage-clamp induced extracellular K accumulation and during perfusion with a K-ricn Ringer solution but small consistent differences are noticed. 4. The measurements of the after-potential, the action potential shortening, and the K-electrode response were analysed as indicators of extracellular K+ activity and it was concluded that the after-potential provides the most convenient and reliable estimate of the absolute magnitude of the voltage-clamp induced extracellular K accumulation. 5. The depolarizing after-potentials decay more slowly than the hyperpolarizing after-potentials but it is found that this reflects the selectivity of the membrane to K+ concentrations as predicted by the Nernst or the Goldman equations. 6. Analysis of the redistribution of accumulated K+ from the decay of the after-potential suggests that the major part of the redistribution process can be described by a single time constant (2--4 sec). A much longer time constant is required for a smaller component of the 'tail' in order to bring [K]o to the normal resting state. 7. N-shaped relations similar to the 'steady state' current-voltage relation are obtained when the post-clamp after-potential, the action potential shortening, and the K-electrode response are plotted versus the clamped membrane potential. The maxima of these curves are located around -40 mV and the minima around -20 mV. 8. In spite of a significant outward membrane current (1--1.5 microamperemeter) in the minimum

  2. Laparoscopic kidney biopsy in dogs: Comparison of cup forceps and core needle biopsy.

    PubMed

    Park, Jiyoung; Lee, Jinwoo; Lee, Hae-Beom; Jeong, Seong Mok

    2017-02-01

    To investigate the feasibility of laparoscopic kidney biopsy with cup biopsy forceps in dogs (CupBF), and to compare to the use of a core biopsy needle (CoreBN). Experimental; randomized, controlled design. Eight healthy, adult Beagle dogs. Dogs were randomized to undergo laparoscopic biopsy of the right kidney using either 5 mm CupBF or a 16 gauge CoreBN. Intraoperative hemorrhage of the biopsy site was monitored. Biopsy quality was evaluated for tissue fragmentation and crushing, presence of renal cortex with or without medulla, and number of glomeruli. Postoperative packed cell volume, urinalysis, and ultrasonographic appearance of the biopsy site were evaluated. Biopsy specimens were obtained by both techniques and reliable hemostasis was achieved with direct compression in all dogs. The histologic score for CupBF biopsies was not significantly different from CoreBN biopsies. One CoreBN biopsy contained both renal cortex and medullar, while all CupBF biopsies contained cortex only. The mean (SD) number of glomeruli was significantly higher in CupBF biopsies [60 (9.1)] than CoreBN biopsies [26 (4.3)]. There was no gross hematuria, perirenal hematoma, or hydronephrosis in any dog postoperative. Laparoscopic kidney biopsy in dogs using 5 mm cup biopsy forceps is feasible with minimal risk and more glomeruli obtained compared to laparoscopic kidney biopsy using 16 gauge core biopsy needles. © 2016 The American College of Veterinary Surgeons.

  3. One 10-core prostate biopsy is superior to two sets of sextant prostate biopsies.

    PubMed

    Fink, K G; Hutarew, G; Pytel, A; Esterbauer, B; Jungwirth, A; Dietze, O; Schmeller, N T

    2003-09-01

    To compare the efficiency of different transrectal ultrasonography (TRUS)-guided prostate biopsy techniques for detecting prostate cancer. In all, 81 prostates from radical prostatectomy were used and two consecutive sets of sextant biopsies and one 10-core biopsy taken in each specimen. The 10-core biopsy consisted of a sextant biopsy and four cores from the far lateral areas of the prostate. To simulate a transrectal biopsy procedure, all biopsies were taken under TRUS guidance. In the first set of sextant biopsies 44 prostate cancers (54%) were detected and in the second set 51 (63%). Combining both sets of sextant biopsies 57 (70%) of the carcinomas were detected. One set of 10-core biopsies detected 66 (82%) of all prostate cancers. Overall, with the 10-core biopsies 16% more prostate tumours were diagnosed than with two consecutive sets of sextant biopsies. To find the same number of prostate cancers as with the 10-core technique, 14% of patients undergoing sextant biopsy would require a second set and 11% at least a third set of biopsies. The 10-core prostate biopsy technique is superior to the commonly used sextant technique and could spare patients unnecessary repeated biopsy. Even after including a second set of sextant biopsies, the total detection rate with these 12 biopsies was inferior to the 10-core technique.

  4. Cell-attached voltage-clamp and current-clamp recording and stimulation techniques in brain slices.

    PubMed

    Perkins, Katherine L

    2006-06-30

    Cell-attached recording provides a way to record the activity of - and to stimulate - neurons in brain slices without rupturing the cell membrane. This review uses theory and experimental data to address the proper application of this technique and the correct interpretation of the data. Voltage-clamp mode is best-suited for recording cell firing activity, and current-clamp mode is best-suited for recording resting membrane potential and synaptic potentials. The magnitude of the seal resistance determines what types of experiments can be accomplished with a cell-attached recording: a loose seal is adequate for recording action potential currents, and a tight seal is required for evoking action potentials in the attached cell and for recording resting and synaptic potentials. When recording action potential currents, if the researcher does not want to change the firing activity of the cell, then it is important that no current passes from the amplifier through the patch resistance. In order to accomplish this condition, the recording pipette should be held at the potential that gives a holding current of 0. An advantage of cell-attached current-clamp over whole-cell recording is that it accurately depicts whether a synaptic potential is hyperpolarizing or depolarizing without the risk of changing its polarity.

  5. Oxidative stress in kidney transplant biopsies.

    PubMed

    Kumar, Avneesh; Hammad, Abdul; Sharma, Ajay K; Mc-Cardle, Frank; Rustom, Rana; Christmas, Steve E

    2015-04-01

    Kidney allograft biopsies are performed after kidney transplant to determine graft dysfunction. We aimed to define and measure the oxidative stress occurring in these biopsies and compared these biopsies with donor pretransplant biopsies. The biopsy procedure was done according to the unit protocol. A core of tissue was taken for research purposes only when it was safe enough to proceed for an extra core. Common indications for biopsy were acute or chronic graft dysfunction, delayed graft function, acute cellular rejection, and calcineurin toxicity. There were 17 pretransplant biopsies taken from deceased-donor kidneys. Biopsy specimens were snap frozen immediately in liquid nitrogen and stored at -70 °C. Samples were processed for Western blot and tested for markers of oxidative stress. There were 61 biopsies analyzed. Oxidative stress enzymes were evaluated by Western blot including catalase, manganese superoxide dismutase, copper zinc superoxide dismutase, thioredoxin reductase, and thioredoxin. Upregulation of most antioxidant enzymes was observed in pretransplant biopsies. Increased expression of manganese superoxide dismutase was observed in donor kidneys and kidneys with acute cellular rejection and calcineurin toxicity. Copper zinc superoxide dismutase and catalase were elevated in donor and acute cellular rejection biopsies. Thioredoxin was elevated in donor biopsies and thioredoxin reductases were elevated in donor biopsies and biopsies with acute cellular rejection and calcineurin toxicity. The kidney allograft biopsies showed that oxidative stress levels were elevated during allograft dysfunction in all biopsies regardless of diagnosis, but not significantly. The levels also were elevated in pretransplant biopsies. The study showed that oxidative stress is involved in various acute injuries occurring within the allograft.

  6. Timing of umbilical cord clamping: new thoughts on an old discussion.

    PubMed

    Arca, Gemma; Botet, Francesc; Palacio, Montse; Carbonell-Estrany, Xavier

    2010-11-01

    The optimal time to clamp the umbilical cord in preterm and full-term neonates after birth continues to be a matter of debate. A review of randomised controlled trials comparing the effects of early versus late cord clamping on maternal and infant outcomes was performed to assess data in favor of immediate or delayed clamping. Although there is no conclusive evidence, delayed cord clamping seems to be beneficial in preterm and full-term neonates without compromising the initial postpartum adaptation phase or affecting the mother in the short term. However, further randomised clinical studies are needed to confirm the benefits of delayed cord clamping.

  7. Ultrasound-Guided Transcutaneous Needle Biopsy of the Base of the Tongue and Floor of the Mouth From a Submental Approach.

    PubMed

    Wagner, Jason M; Conrad, Rachel D; Cannon, Trinitia Y; Alleman, Anthony M

    2016-05-01

    Limited data exist regarding the feasibility of ultrasound-guided transcutaneous biopsy of the base of the tongue and floor of the mouth. This retrospective study reviewed 8 cases with lesions in the base of the tongue or floor of the mouth that were biopsied by fine-needle aspiration. Core biopsy was also needed in 1 case. All biopsies were technically successful, and all yielded squamous cell carcinoma. One biopsy yielded a false-positive result, as subsequent resection yielded high-grade dysplasia with no invasion. The other biopsy results were considered true-positive based on subsequent pathologic examinations (2 cases) or clinical/imaging follow-up (5 cases). There were no significant complications associated with the biopsies. © 2016 by the American Institute of Ultrasound in Medicine.

  8. Medical Thoracoscopy vs Closed Pleural Biopsy in Pleural Effusions: A Randomized Controlled Study.

    PubMed

    Haridas, Nithya; K P, Suraj; T P, Rajagopal; P T, James; Chetambath, Ravindran

    2014-05-01

    Pleural effusion is a common diagnostic dilemma for the pulmonologist. A histological diagnosis would many a time steer the way to an accurate diagnosis of the aetiologies of pleural effusions. This study has compared two methods for obtaining histological specimens in cases of undiagnosed pleural effusions. To compare the efficacy of closed pleural biopsy with Abrahm's needle and medical thoracoscopic biopsy in the diagnosis of undiagnosed exudative pleural effusions at a tertiary care setting. Randomized controlled study. November 2008-October 2010. All patients who were admitted with pleural effusions underwent a clinical workup for pleural effusions. Light's criterion was used to differentiate between exudative and transudative pleural effusions. Those patients with exudative pleural effusions, who did not have a specific diagnosis, were included in the study. Fifty eight patients were included in the study and they were randomized into 2 Groups of 29 patients each. One group was subjected to medical thoracoscopic pleural biopsy and the other to closed pleural biopsy with Abrahm's needle. Demographic, clinical and biochemical characteristics, diagnostic yields and the complications among the two groups were compared. Medical thoracoscopy has a diagnostic yield of 86.2% with complication rate of 10.3% compared to 62.1% and 17.2% respectively in closed pleural biopsy group. Medical thoracoscopic pleural biopsy had a better diagnostic yield with a lower complication rate as compared to closed pleural biopsy with Abrahm's needle.

  9. The future prospect: ductoscopy-directed brushing and biopsy.

    PubMed

    Dooley, William Chesnut

    2005-12-01

    The intraductal approach to breast cancer and premalignant lesions has now developed to yield substantial cytologic samples of exfoliated cells. Standard cytology is still inadequate in sensitivity and specificity to accurately interpret the majority of samples. As techniques evolve using ductoscopic biopsy and molecular marker panels to increase accuracy of cytologic interpretation, these tools will be able to unravel the breast carcinogenesis pathways. They will also offer considerable benefit in screening for premalignant changes and developing effective chemoprevention strategies.

  10. Clamping stiffness and its influence on load distribution between paired internal spinal fixation devices.

    PubMed

    Rohlmann, A; Calisse, J; Bergmann, G; Radvan, J; Mayer, H M

    1996-06-01

    The load distribution between two internal spinal fixation devices depends, besides other factors, on their stiffness. The stiffness ranges were determined experimentally for the clamps of the AO internal fixator with lateral nut and with posterior nut as well as for the clamps of the SOCON fixator. The stiffness of eight devices each differed by a factor of 3.1 for the clamp with lateral nut, by a factor of 1.5 for the clamp with posterior nut, and by a factor of 1.4 for the clamp of the SOCON fixator. For the AO clamp with lateral nut, the influence of the nut-tightening torque on the stiffness was determined. Using instrumented internal spinal fixation devices mounted to plastic vertebrae and simulating a corpectomy, the load distribution between the implants was measured for different tightening torques. It could be shown that, for the AO internal fixator whose clamps have a lateral nut, a nut-tightening torque > 5 Nm has only a negligible influence on load-sharing between the implants. Tooth damage occurs when the teeth of the clamp body and clamping jaw of the clamp with lateral nut do not gear together exactly, which leads to changes in the clamping stiffness and load-sharing between the two implants.

  11. Testing Biopsy and Cytology Specimens for Cancer

    MedlinePlus

    ... Exams and Tests for Cancer Testing Biopsy and Cytology Specimens for Cancer Waiting to hear test results ... biopsies used to look for cancer Types of cytology tests used to look for cancer What happens ...

  12. Melanoma Biopsy Results Can Differ, Worrying Patients

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_166955.html Melanoma Biopsy Results Can Differ, Worrying Patients Doctor discovers ... her dermatologist said her skin biopsy indicated possible melanoma, she knew just what to do -- get a ...

  13. Liquid biopsy in liver cancer.

    PubMed

    Labgaa, Ismail; Villanueva, Augusto

    2015-04-01

    Liver cancer has become the second cause of cancer-related death worldwide. Most patients are still diagnosed at intermediate or advanced stage, where potentially curative treatment options are not recommended. Unlike other solid tumors, there are no validated oncogenic addiction loops and the only systemic agent to improve survival in advanced disease is sorafenib. All phase 3 clinical trials testing molecular therapies after sorafenib have been negative, none of which selected patients based on predictive biomarkers of response. Theoretically, analysis of circulating cancer byproducts (e.g., circulating tumor cells, cell-free nucleic acids), namely "liquid biopsy," could provide easy access to molecular tumor information, improve patients' stratification and allow to assess tumor dynamics over time. Recent technical developments and preliminary data from other malignancies indicate that liquid biopsy might have a role in the future management of cancer patients.

  14. Biopsy

    MedlinePlus

    ... Osteopathic Medicine Disease Database Contributors Doctor Derm App Skin Facts Aging and Sun Damage Beauty Myths Preventing Sun Damage Skin Cancer Detection Skin Disease Links Sun Safety Document ...

  15. Biopsies

    MedlinePlus

    ... taking, including blood thinners such as aspirin and herbal supplements, and whether you have any allergies – especially to ... doctor all medications that you are taking, including herbal supplements, and if you have any allergies, especially to ...

  16. Evaluation of transition zone and lateral sextant biopsies for prostate cancer detection after initial sextant biopsy.

    PubMed

    Fink, Klaus G; Hutarew, Georg; Esterbauer, Brigitte; Pytel, Akos; Jungwirth, Andreas; Dietze, Otto; Schmeller, Nikolaus T

    2003-04-01

    To assess the value of transition zone and lateral sextant biopsies for the detection of prostate cancer after a previous sextant biopsy was negative. A total of 74 prostates after radical prostatectomy were used to perform biopsies ex vivo. First, a sextant biopsy was taken, then two different rebiopsy techniques were performed. Rebiopsy technique A consisted of a laterally placed sextant biopsy and two cores per side of the transition zones only. Rebiopsy technique B included a standard sextant biopsy and two cores per side from the lateral areas of the prostate. The biopsies were taken using ultrasound guidance to sample the areas of interest precisely. The initial sextant biopsy found 39 prostate cancers. Rebiopsy technique A found 12 cancers (34%). In this group, a laterally placed sextant biopsy found 12 cancers; transition zone biopsies revealed cancer in 5 cases, but no additional tumor was found. Rebiopsy technique B detected 23 prostate cancers (66%). Fourteen tumors were found after a second standard sextant biopsy, and nine additional tumors were found in the lateral areas. Sextant biopsy has a low sensitivity of only 53%. A biopsy including the transition zones is not the ideal technique for detecting the remaining tumors. Therefore, transition zone biopsies should be reserved for patients with multiple previous negative biopsies of the peripheral zone. A subsequent sextant biopsy with additional cores from the lateral areas of the prostate is favorable if rebiopsy is necessary after a negative sextant biopsy.

  17. Skin biopsy as an additional diagnostic tool in non-systemic vasculitic neuropathy.

    PubMed

    Uçeyler, Nurcan; Devigili, Grazia; Toyka, Klaus V; Sommer, Claudia

    2010-07-01

    Sural nerve biopsy is considered mandatory for diagnosing non-systemic vasculitic neuropathy (NSVN). This invasive technique may be associated with unpleasant sequelae and cannot easily be repeated. Skin punch biopsy from an affected area may be a less invasive and repeatable diagnostic method. Here we assessed the potential diagnostic value of skin punch biopsies in NSVN by analyzing skin biopsies in 20 patients with sural nerve biopsy-proven NSVN and in 11 patients with non-inflammatory axonal neuropathy. As further controls, skin biopsies were studied in nine healthy volunteers. Five millimeter skin punch biopsies were taken under local anesthesia from the distal lateral calf and T cells and macrophages were quantified after immunostaining. The diagnostic sensitivity and specificity compared to sural nerve biopsy was determined using receiver operating characteristic (ROC) analysis. ROC analysis revealed that the highest sensitivity (94%) and specificity (79%) for NSVN was obtained when perivascular macrophages were quantified. Quantification of scattered T cells yielded a sensitivity and specificity of 65%. Inflammatory cells were very rare in controls. Quantification of inflammatory cells in skin biopsies may thus be a sensitive and specific additional tool for diagnosing NSVN.

  18. Liver biopsy for parenchymal liver disease - is routine real time image guidance unnecessary?

    PubMed

    John, Anil; Al Kaabi, Saad; Soofi, Madiha Emran; Mohannadi, Muneera; Kandath, Salva Manam; Derbala, Moataz; Yakoub, Rafie; Al-Ahdal, Esra Mohammed; Sharma, Manik; Wani, Hamid; Dweik, Nazeeh; John, Anjum; Butt, Mohammed Tariq

    2014-01-01

    Liver biopsy even today remains the standard of care for grading and staging chronic hepatitis despite advances in noninvasive markers of liver fibrosis. Literature suggests an expanding role for real-time image guided liver biopsy and declining trend for blind liver biopsies. In our center, where we perform around 400 liver biopsies per year, we performed a prospective clinical audit of our practice of blind outpatient percutaneous liver biopsies. Patients requiring histological grading and staging of chronic hepatitis routinely undergo blind outpatient percutaneous liver biopsies in our endoscopy unit unless there is a definite indication for real-time image guidance. All procedures were assessed for safety, and all specimens were evaluated by a specimen quality grading score for adequacy for grading and staging of chronic hepatitis. Of the 446 patients referred for histological grading and staging of chronic hepatitis C by liver biopsy, only 42 patients (9.5 %) required real-time ultrasound for liver biopsy. The remaining 404 patients underwent blind outpatient percutaneous liver biopsies which were found to be extremely safe with no major complications, yielding adequate liver tissue with high specimen quality score allowing optimal grading and staging of chronic hepatitis.

  19. Core Needle Biopsy and Fine Needle Aspiration Alone or in Combination: Diagnostic Accuracy and Impact on Management of Renal Masses.

    PubMed

    Cate, Frances; Kapp, Meghan E; Arnold, Shanna A; Gellert, Lan L; Hameed, Omar; Clark, Peter E; Wile, Geoffrey; Coogan, Alice; Giannico, Giovanna A

    2017-06-01

    Fine needle aspiration with and without concurrent core needle biopsy is a minimally invasive method to diagnose and assist in management of renal masses. We assessed the pathological accuracy of fine needle aspiration compared to and associated with core needle biopsy and the impact on management. We performed a single institution, retrospective study of 342 cases from 2001 to 2015 with small and large renal masses (4 or less and greater than 4 cm, respectively). Diagnostic and concordance rates, and the impact on management were analyzed. Adequacy rates for fine needle aspiration only, core needle biopsy only and fine needle aspiration plus core needle biopsy were 21%, 12% and 8% (aspiration vs aspiration plus biopsy p <0.026). In the aspiration plus biopsy group adding aspiration to biopsy and biopsy to aspiration reduced the inadequacy rate from 23% to 8% and from 27% to 8% for a total reduction rate of 15% and 19%, respectively, corresponding to 32 cases (9.3%). Rapid on-site examination contributed to a 22.5% improvement in fine needle aspiration adequacy rates. In this cohort 30% of aspiration only, 5% of biopsy only and 12% of aspiration plus biopsy could not be subtyped (aspiration vs biopsy p <0.0001, aspiration vs aspiration plus biopsy p <0.0127 and biopsy vs aspiration plus biopsy p = 0.06). The diagnostic concordance rate with surgical resection was 99%. Conversion of an inadequate specimen to an adequate one by a concurrent procedure impacted treatment in at least 29 of 32 patients. Limitations include the retrospective design and accuracy measurement based on surgical intervention. Fine needle aspiration plus core needle biopsy vs at least fine needle aspiration alone may improve diagnostic yield when sampling renal masses but it has subtyping potential similar to that of core needle biopsy only. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  20. Efficiency of Prostate Cancer Diagnosis by MR/Ultrasound Fusion-Guided Biopsy vs Standard Extended-Sextant Biopsy for MR-Visible Lesions.

    PubMed

    Siddiqui, M Minhaj; George, Arvin K; Rubin, Rachel; Rais-Bahrami, Soroush; Parnes, Howard L; Merino, Maria J; Simon, Richard M; Turkbey, Baris; Choyke, Peter L; Wood, Bradford J; Pinto, Peter A

    2016-09-01

    Use of magnetic resonance (MR) imaging to improve prostate biopsy efficiency is rapidly gaining in popularity. The aim of this study was to assess the biopsy efficiency of MR/ultrasound (MR/US) fusion-guided ("targeted") biopsies vs extended-sextant 12-core ("standard") biopsies for overall and high-grade prostate cancer detection. From August 2007 to February 2014, 1003 men were enrolled in a prospective trial comparing the diagnostic yield of targeted and standard prostate biopsies performed during the same session. A total of 17 619 biopsy cores were reviewed. Biopsy efficiency was determined by dividing the total number of cores by the number of positive cores obtained. All statistical tests were two-sided. A mean of 12.3 (95% confidence interval [CI] = 12.2 to 12.3) standard and 5.3 (95% CI = 5.1 to 5.5) targeted biopsy cores were obtained from each patient. Targeted biopsy detected 461 cases of prostate cancer, of which 173 (37.5%) were high grade (Gleason score ≥ 4 + 3), while standard biopsy detected 469 cases of prostate cancer, of which 122 (26.5%) were high grade. The percentage of biopsy cores positive for prostate cancer, irrespective of grade, was statistically significantly higher for targeted than for standard biopsies (27.9% vs 13.5%, respectively, P < .001), with 11.5 targeted cores vs 26.2 standard cores utilized per diagnosis of prostate cancer. For detection of high-grade cancer, 30.7 targeted vs 100.8 standard cores were utilized per diagnosis. In men with MR-visible prostate lesions, targeted biopsy is more efficient than standard biopsy, diagnosing a similar number of cancer cases and more high-grade cases while sampling 56.1% fewer biopsy cores. Published by Oxford University Press 2016. This work is written by US Government employees and is in the public domain in the United States.

  1. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    PubMed Central

    Kukshal, Vandna; Khanam, Taran; Chopra, Deepti; Singh, Nidhi; Sanyal, Sabyasachi; Ramachandran, Ravishankar

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C2221 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent Kd of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD+ -dependent DNA ligase (LigA) and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria. PMID:22545130

  2. Umbilical cord clamping at birth--practice in Norwegian maternity wards.

    PubMed

    Lundberg, Camilla; Øian, Pål; Klingenberg, Claus

    2013-11-26

    The timing and practice used for umbilical cord clamping of neonates are controversial internationally as well as in Norway. We therefore wished to investigate routines and practices for umbilical cord clamping of neonates in Norway. A web-based questionnaire was sent to heads of departments of all maternity wards in Norway (n = 52). They were asked about their practice with regard to umbilical cord clamping of neonates and whether written routines had been prepared for this purpose. We defined early umbilical cord clamping as immediate or within 30 seconds and late clamping as ≥ 1 minute or not until pulsation in the umbilical cord had ceased. Fifty (96%) of the maternity institutions returned a completed questionnaire. Twelve institutions (24%) reported to clamp the umbilical cord of full-term neonates early, and 38 (76%) reported to practise late clamping. Nineteen maternity wards (38%) followed written routines for umbilical cord clamping of full-term neonates, and among these, early umbilical cord clamping was practised in nine (47%). In the 31 maternity wards that had no written routines, early umbilical cord clamping was practised in three (10%). Twenty-seven of the maternity wards reported that the child is placed on the maternal abdomen before clamping of the umbilical cord, 14 reported that the child commonly is held below the introitus before umbilical cord clamping, and the rest did not report any consistent practice. There is wide variation in the practice for umbilical cord clamping in Norwegian maternity wards, many of which have no written guidelines. We argue that national guidelines for umbilical cord clamping of neonates should be established.

  3. 20 CFR 718.106 - Autopsy; biopsy.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Autopsy; biopsy. 718.106 Section 718.106... DUE TO PNEUMOCONIOSIS Criteria for the Development of Medical Evidence § 718.106 Autopsy; biopsy. (a) A report of an autopsy or biopsy submitted in connection with a claim shall include a detailed gross...

  4. 20 CFR 718.106 - Autopsy; biopsy.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Autopsy; biopsy. 718.106 Section 718.106... DUE TO PNEUMOCONIOSIS Criteria for the Development of Medical Evidence § 718.106 Autopsy; biopsy. (a) A report of an autopsy or biopsy submitted in connection with a claim shall include a detailed gross...

  5. Analysis of motion during the breast clamping phase of mammography.

    PubMed

    Ma, Wang Kei; McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p < 0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p < 0.001). Paddle tilt in the medial-lateral plane is independent of time and varied from 0.04 ° to 0.69 °. All machine/paddle combinations exhibited motion and tilting, and the extent varied with machine and paddle sizes and types. This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences.

  6. Analysis of motion during the breast clamping phase of mammography

    PubMed Central

    McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    Objective: To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. Methods: A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial–lateral plane for each machine/paddle combination was calculated. Results: All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p < 0.001), GE Senographe Essential and Hologic Selenia Dimensions paddles (p < 0.001). Paddle tilt in the medial–lateral plane is independent of time and varied from 0.04 ° to 0.69 °. Conclusion: All machine/paddle combinations exhibited motion and tilting, and the extent varied with machine and paddle sizes and types. Advances in knowledge: This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences. PMID:26739577

  7. Nonlinear vibrations of fluid-filled clamped circular cylindrical shells

    NASA Astrophysics Data System (ADS)

    Karagiozis, K. N.; Amabili, M.; Païdoussis, M. P.; Misra, A. K.

    2005-12-01

    In this study, the nonlinear vibrations are investigated of circular cylindrical shells, empty or fluid-filled, clamped at both ends and subjected to a radial harmonic force excitation. Two different theoretical models are developed. In the first model, the standard form of the Donnell's nonlinear shallow-shell equations is used; in the second, the equations of motion are derived by a variational approach which permits the inclusion of constraining springs at the shell extremities and taking in-plane inertial terms into account. In both cases, the solution includes both driven and companion modes, thus allowing for a travelling wave in the circumferential direction; they also include axisymmetric modes to capture the nonlinear inward shell contraction and the correct type (softening) nonlinear behaviour observed in experiments. In the first model, the clamped beam eigenfunctions are used to describe the axial variations of the shell deformation, automatically satisfying the boundary conditions, leading to a 7 degree-of-freedom (dof) expansion for the solution. In the second model, rotational springs are used at the ends of the shell, which when large enough reproduce a clamped end; the solution involves a sine series for axial variations of the shell deformation, leading to a 54 dof expansion for the solution. In both cases the modal expansions satisfy the boundary conditions and the circumferential continuity condition exactly. The Galerkin method is used to discretize the equations of motion, and AUTO to integrate the discretized equations numerically. When the shells are fluid-filled, the fluid is assumed to be incompressible and inviscid, and the fluid structure interaction is described by linear potential flow theory. The results from the two theoretical models are compared with existing experimental data, and in all cases good qualitative and quantitative agreement is observed.

  8. Clamped seismic metamaterials: ultra-low frequency stop bands

    NASA Astrophysics Data System (ADS)

    Achaoui, Y.; Antonakakis, T.; Brûlé, S.; Craster, R. V.; Enoch, S.; Guenneau, S.

    2017-06-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1-10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0-30 Hz.

  9. Core needle biopsy of thyroid nodules - evaluation of diagnostic utility and pain experience.

    PubMed

    Stangierski, Adam; Wolinski, Kosma; Martin, Karolina; Leitgeber, Olena; Ruchala, Marek

    2013-01-01

    A crucial problem in the non-operative diagnosis of thyroid nodules is the significant amount of non-diagnostic biopsies. This is a challenge for practicing endocrinologists especially when the results of the repeated biopsies remain non-diagnostic. The lack of a concrete preoperative diagnosis may result in unnecessary thyroidectomies in patients. Alternatively, it may also lead to the delayed diagnosis of cancer. One method of biopsy specimen acquisition that could potentially increase the diagnostic accuracy of thyroid biopsies is the application of core-needles. The aim of the study was to compare the diagnostic value and patient tolerability of core-needle aspiration biopsies (CNAB) with fine-needle aspiration biopsies (FNAB). The study included patients with thyroid nodular goiter in whom previous conventional FNAB yielded non-diagnostic results. CNABs were performed using 22G core-needles. The control group consisted of patients undergoing conventional FNAB with 25G fine-needles. Pain during core-needle biopsies of thyroid nodules was assessed using the 10-point visual analog scale. There were a total of 30 lesions in 26 patients undergoing CNAB (22 women, 4 men, mean age 48.3) and a total of 59 lesions in 40 patients undergoing FNAB (34 women, 6 men, mean age 57.3). 56.6% of CNABs and 50.8% of FNABs were diagnostic (p=0.60). When assessing pain via the visual analog scale, the median score for biopsies performed with core-needles was four. 60.0% of patients considered the pain of core-needle aspiration biopsies to be similar to the pain experienced during the previous conventional fine-needle aspiration biopsies, while 40% of patients claimed that the pain was more intense. CNAB did not prove to be superior to FNAB. Despite the larger needle gauge used during core-needle biopsies, the patients' tolerability was comparable to conventional fine-needle biopsies.

  10. A comparison of suction and full-thickness rectal biopsy in children.

    PubMed

    Muise, Eleanor D; Hardee, Steven; Morotti, Raffaella A; Cowles, Robert A

    2016-03-01

    Rectal biopsy evaluation by an experienced pathologist is the gold standard in diagnosis of Hirschsprung's disease (HD). Although both suction rectal biopsy (SRB) and full-thickness (FTRB) rectal biopsy are performed, the ability for SRB to obtain adequate tissue in older children has been questioned. We hypothesized that SRB and FTRB yield tissue specimens of different size but are equally adequate for diagnosis. Records of children who underwent rectal biopsy to evaluate for HD between January 2007 and July 2014 were reviewed. Volume, percent submucosa, and specimen adequacy were compared between biopsy techniques, and the effect of age on biopsy adequacy was assessed. Data were analyzed by mixed-effects models with covariate adjustment for age at biopsy and Fisher's exact test. Forty-seven children underwent a total of 58 biopsies, 45 SRB and 13 FTRB. Thirty-seven were performed before 12 mo of age, and 21 after 12 mo of age. Volume of SRB specimens was significantly smaller than FTRB across ages (14.8 ± 7.8 mm(3)versus 121.3 ± 13.8 mm(3), P = 0.0001). Percent submucosa did not differ significantly between SRB and FTRB specimens across ages (63.8 ± 2.7% versus 66.5 ± 4.3%, P = 0.575). The number of inadequate biopsies was low and not significantly different across ages (P = 0.345), or when comparing by biopsy method (P = 0.689). All biopsies were clinically diagnostic. There were no complications. Tissue specimens obtained by SRB are smaller than those obtained by FTRB, especially in older children. SRB and FTRB appear equivalent in their ability to provide adequate submucosa. Differences in cost and patient satisfaction between rectal biopsy techniques must be studied to further define the best overall technique. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Suction-modified needle biopsy technique for the human soleus muscle

    PubMed Central

    Cotter, Joshua A.; Yu, Alvin; Kreitenberg, Arthur; Haddad, Fadia H.; Baker, Michael J.; Fox, John C.; Adams, Gregory R.

    2014-01-01

    INTRODUCTION The needle biopsy technique for the soleus muscle is of particular interest because of its unique fiber type distribution, contractile properties, and sensitivity to unloading. Unlike other commonly biopsied muscles, the soleus is not fully superficial and is in close proximity to neurovascular structures resulting in a more challenging biopsy. Because of this, a standardized protocol for performing needle biopsies on the human soleus muscle that is safe, reliable, and repeatable is presented. METHODS Ultrasonography was used on an initial set of 12 subjects to determine the optimal biopsy zone thereby guiding the location of the incision site. Forty-five subjects were recruited and attended two separate biopsy sessions. Each biopsy session incorporated 3 passes of the biopsy needle proximal, posterior, and distal using suction from a portable vacuum source producing 3 separate muscle specimens. RESULTS Eighty-four soleus muscle biopsy procedures were successfully conducted yielding 252 total samples without complication. Ultrasonography was used to confirm biopsy needle infiltration of the soleus muscle. Average sample weight obtained per pass was 61.5 ± 15.7 mg. Histochemistry and molecular analyses demonstrated a considerably higher amount of slow type I MHC in comparison to the vastus lateralis providing verification for the successful sampling of the soleus muscle. DISCUSSION The procedure presented consists of a detailed protocol to accurately and consistently obtain muscle biopsy samples from the human soleus muscle. We have demonstrated that the human soleus biopsy is a safe, reliable and repeatable procedure providing ample tissue for multiple types of analyses. PMID:24261060

  12. Accessible or Inaccessible? Diagnostic Efficacy of CT-Guided Core Biopsies of Head and Neck Masses

    SciTech Connect

    Cunningham, Jane D. McCusker, Mark W.; Power, Sarah; PearlyTi, Joanna; Thornton, John; Brennan, Paul; Lee, Michael J.; O’Hare, Alan; Looby, Seamus

    2015-04-15

    PurposeTissue sampling of lesions in the head and neck is challenging due to complex regional anatomy and sometimes necessitates open surgical biopsy. However, many patients are poor surgical candidates due to comorbidity. Thus, we evaluated the use of CT guidance for establishing histopathological diagnosis of head and neck masses.MethodsAll consecutive patients (n = 22) who underwent CT-guided core biopsy of head or neck masses between April 2009 and August 2012 were retrospectively reviewed using the departmental CT interventional procedures database. The indication for each biopsy performed was to establish or exclude a diagnosis of neoplasia in patients with suspicious head or neck lesions found on clinical examination or imaging studies. Patients received conscious sedation and 18 G, semiautomated core needle biopsies were performed by experienced neuroradiologists using 16-slice multidetector row CT imaging guidance (Somatom Definition Siemens Medical Solutions, Germany). Histopathology results of each biopsy were analysed.ResultsSixteen of 22 biopsies that were performed (73 %) yielded a pathological diagnosis. Anatomic locations biopsied included: masticator (n = 7), parapharyngeal (n = 3), parotid (n = 3), carotid (n = 3), perivertebral (n = 3), pharyngeal (n = 2), and retropharyngeal (n = 1) spaces. Six biopsies (27 %) were nondiagnostic due to inadequate tissue sampling, particularly small biopsy sample size and failure to biopsy the true sampling site due to extensive necrosis. No major complications were encountered.ConclusionsThe use of CT guidance to perform core biopsies of head and neck masses is an effective means of establishing histopathological diagnosis and reduces the need for diagnostic open surgical biopsy and general anaesthesia.

  13. When to biopsy seminal vesicles.

    PubMed

    Panach-Navarrete, J; García-Morata, F; Hernández-Medina, J A; Martínez-Jabaloyas, J M

    2015-05-01

    The involvement of seminal vesicles in prostate cancer can affect the prognosis and determine the treatment. The objective of this study was to determine whether we could predict its infiltration at the time of the prostate biopsy to know when to indicate the biopsy of the seminal vesicles. observational retrospective study of 466 patients who underwent seminal vesicle biopsy. The indication for this biopsy was a prostate-specific antigen (PSA) level greater than 10 ng/ml or an asymmetric or obliterated prostatoseminal angle. The following variables were included in the analysis: PSA level, PSA density, prostate volume, number of cores biopsied, suspicious rectal examination, and preservation of the prostatoseminal angle, studying its relationship with the involvement of the seminal vesicles. Forty-one patients (8.8%) had infiltrated seminal vesicles and 425 (91.2%) had no involvement. In the univariate analysis, the cases with infiltration had a higher mean PSA level (P < .01) and PSA density (P < .01), as well as a lower mean prostate volume (P < .01). A suspicious rectal examination (20.7% of the infiltrated vesicles) and the obliteration or asymmetry of the prostatoseminal angle (33.3% of the infiltrated vesicles) were significantly related to the involvement (P < .01). In the multivariate analysis, we concluded that the probability of having infiltrated seminal vesicles is 5.19 times higher if the prostatoseminal angle is not preserved (P < .01), 4.65 times higher for PSA levels >19.60 ng/dL (P < .01) and 2.95 times higher if there is a suspicious rectal examination (P = .014). Furthermore, this probability increases by 1.04 times for each unit of prostate volume lower (P < .01). The ROC curves showed maximum sensitivity and specificity at 19.6 ng/mL for PSA and 0.39 for PSA density. In this series, greater involvement of seminal vesicles was associated with a PSA level ≥20 ng/ml, a suspicious rectal examination and a lack of prostatoseminal angle

  14. Detection of viral hepatitis E in clinical liver biopsies.

    PubMed

    Prost, Sandrine; Crossan, Claire L; Dalton, Harry R; De Man, Robert A; Kamar, Nassim; Selves, Janick; Dhaliwal, Catharine; Scobie, Linda; Bellamy, Christopher O C

    2017-10-01

    To determine the relative utility of in-situ testing for hepatitis E virus (HEV) RNA and paraffin-section polymerase chain reaction (PCR) to diagnose HEV infection in paraffin-embedded clinical liver biopsies, and to correlate with clinicopathological characteristics. We evaluated in-situ and quantitative PCR (qPCR)-based approaches to identifying HEV in clinical liver biopsies from infected patients from multiple centres, correlating with clinical setting (immunocompetent, allograft or immunosuppressed native liver) and histological findings. Thirty-six biopsies from 29 patients had histological data, 27 and 23 of which had satisfactory material for in-situ RNA testing and tissue qPCR, respectively. Both approaches specifically identified HEV infection, but tissue qPCR was significantly more sensitive than RNAscope in-situ testing (P = 0.035). In immunocompetent but not immunosuppressed patients the tissue qPCR yield correlated with the severity of lobular hepatitis (rho = 0.94, P < 0.001). qPCR viral yield was comparably high in allografts and immunosuppressed native livers and significantly greater than with native liver infection. Immunosuppressed patients showed reduced severity of hepatitis and cholestatic changes, compared with immunocompetent patients. Indeed, HEV-infected liver allografts could show minimal hepatitis for many months. In individual cases each technique was useful when serum was not available to identify chronic infection retrospectively (in biopsies taken 4-31 months before diagnosis), to identify persistent/residual infection when contemporary serum PCR was negative and to identify cleared infection. qPCR is more effective than in-situ RNA testing to identify HEV infection in paraffin-embedded liver biopsies and has diagnostic utility in selected settings. © 2017 John Wiley & Sons Ltd.

  15. Nanomechanics of PCNA: A protein-made DNA sliding clamp

    NASA Astrophysics Data System (ADS)

    Rydzewski, Jakub; Strzalka, Wojciech; Nowak, Wieslaw

    2015-08-01

    Proliferating Cell Nuclear Antigen (PCNA) is a homotrimeric DNA sliding clamp involved in DNA replication, repair and cell cycle control. Understanding determinants of mechanical stability of a PCNA monomer composed of two N- and C-terminal domains requires all-atom and coarse-grained steered molecular dynamics simulations. Three schemes of unfolding at a single molecule level indicate that the conserved curvature of the PCNA monomer is due to aggregation of side β-sheets. The force spectra suggest that rupturing an interface between the domains is less probable than opening an interface between the two monomers during PCNA loading onto DNA by Replication Factor C.

  16. Normal-Pressure Tests of Circular Plates with Clamped Edges

    NASA Technical Reports Server (NTRS)

    Mcpherson, Albert E; Ramberg, Walter; Levy, Samuel

    1942-01-01

    A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness form 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of the permanent set as a function of the dimensions of the plate and the tensile properties of the material.

  17. [Time of cord clamping and neonatal complications, a prospective study].

    PubMed

    Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

    2014-09-01

    To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (<60 seconds), group 2 (1 to<2 minutes), and group 3 (2 to 3 minutes). Laboratory tests were performed at birth and at 48 hours of life, assessing the levels of hemoglobin, hematocrit, ferritin, and bilirubin. The risk of polycythemia, respiratory distress syndrome, neonatal phototherapy or admission to the Intensive Care Unit and the hospital stay, were evaluated. A total of 242 patients were included: group 1 (g1=80), group 2 (g2=31) y group 3 (g3=131). The background maternal and neonatal characteristics were similar in all sets. The first test showed significant differences in ferritin levels in those infants with delayed clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; p<0.01). In the second analysis the values of hemoglobin (g1: 17.3 g/dl, g2: 18.9 g/dl, g3: 19.2 g/dl; p<0.01), hematocrit (g1: 53.4%, g2: 58%, g3: 59%; p<0.01) and ferritin (g1: 254 mg/dl, g2: 254.7 mg/dl, g3: 313 mg/dl; p = 0.008) were statistically higher in this group. As regards complications, a significant increase was observed in the number of cases of polycythemia symptoms in group 3. The late cord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  18. Timing of umbilical cord clamping and neonatal haematological status.

    PubMed

    Jaleel, Riffat; Deeba, Farah; Khan, Ayesha

    2009-07-01

    To determine the effect of delayed umbilical cord clamping on Hb (haemoglobin) and bilirubin levels of neonates and to identify newborn babies with anaemia and refer them for treatment. This Randomized Controlled Trial was conducted in the Department of Obstetrics and Gynaecology, Unit V, Dow Medical College and Lyari General Hospital and Department of Pathology, Lyari General Hospital, between 1st November, 2006 and 15th July, 2007. Patients admitted to labour ward were selected according to inclusion criteria of the study. They were randomly allocated to 2 groups. Group A included women in whom umbilical cord was clamped immediately after birth. In Group B, clamping was delayed until cessation of pulsations in the cord. After cutting the cord, sample of blood was collected from the cut end of cord of the newborn for Hb and bilirubin. After 6 hours of birth, another sample of blood was drawn from antecubital vein for serum bilirubin. Samples were sent to laboratory for analysis. All data were entered and analyzed using SPSS version 11. Two hundred women were studied, 100 in each of the 2 groups. Mean maternal Hb was 9.75 g/dl in Group A and 9.95 g/dl in Group B. The average neonatal Hb was 14.1 g/dl in Group A and 15.2 g/dl in Group B (p = 0.008). In all 49% neonates in Group A and 37% in Group B had Hb < 14 g/dl. Serum bilirubin values at birth and at 6 hours of birth were 1.8 mg/dl and 2.5 mg/dl for Group A and 1.9 mg/dl and 2.7 mg/dl for Group B, respectively. The difference in bilirubin after 6 hours in the 2 groups was insignificant (p = 0.186). Delayed umbilical cord clamping at birth seems to be safe and can be expected to reduce the prevalence of anaemic newborn babies in our community.

  19. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    NASA Astrophysics Data System (ADS)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  20. Normal-pressure Tests of Circular Plates with Clamped Edges

    NASA Technical Reports Server (NTRS)

    Mcpherson, Albert E; Ramberg, Walter; Levy, Samuel

    1942-01-01

    A fixture is described for making normal-pressure tests of flat plates 5 inches in diameter in which particular care was taken to obtain rigid clamping at the edges. Results are given for 19 plates, ranging in thickness from 0.015 to 0.072 inch. The center deflections and the extreme-fiber stresses at low pressures were found to agree with theoretical values; the center deflections at high pressures were 4 to 12 percent greater than the theoretical values. Empirical curves are derived of the pressure for the beginning of permanent set as a function of the dimensions of the plate and the tensile properties of the material.

  1. From unwinding to clamping - the DEAD box RNA helicase family.

    PubMed

    Linder, Patrick; Jankowsky, Eckhard

    2011-07-22

    RNA helicases of the DEAD box family are present in all eukaryotic cells and in many bacteria and Archaea. These highly conserved enzymes are required for RNA metabolism from transcription to degradation and are therefore important players in gene expression. DEAD box proteins use ATP to unwind short duplex RNA in an unusual fashion and remodel RNA-protein complexes, but they can also function as ATP-dependent RNA clamps to provide nucleation centres that establish larger RNA-protein complexes. Structural, mechanistic and molecular biological studies have started to reveal how these conserved proteins can perform such diverse functions and how accessory proteins have a central role in their regulation.

  2. Limitations of preoperative biopsy in patients with metastatic renal cell carcinoma: comparison to surgical pathology in 405 cases.

    PubMed

    Abel, E Jason; Carrasco, Alonso; Culp, Stephen H; Matin, Surena F; Tamboli, Pheroze; Tannir, Nizar M; Wood, Christopher G

    2012-12-01

    Study Type--Diagnostic (cohort) Level of Evidence: 2b. What's known on the subject? and What does the study add? Although there have been many investigations of biopsy for small renal masses, there are scant data on the accuracy of biopsy in the setting of metastatic renal cell carcinoma (mRCC). We report a large series of biopsies and compare with nephrectomy pathology in patients with mRCC. The present study highlights the inaccuracy of biopsy in the setting of metastatic disease, which is related to sampling error because of heterogeneity within the tumour and among metastases. These limitations are important to realize when designing trials that depend on pathological findings from biopsy and not nephrectomy. In addition, we found that biopsy of primary tumours were more likely than biopsy of metastatic sites to be diagnostic of RCC. Future studies with multiquadrant biopsies of primary tumours could yield the most accurate pathological results for future studies. • To evaluate the ability of preoperative biopsy to identify high-risk pathological features by comparing pathology from preoperative metastatic site and primary tumour biopsies with nephrectomy pathology in patients with metastatic renal cell carcinoma (mRCC). •  We reviewed clinical and pathological data from patients who underwent biopsy before cytoreductive nephrectomy for mRCC at MD Anderson Cancer Center (MDACC) from 1991 to 2007. • Percutaneous biopsy techniques included fine-needle aspiration, core needle biopsy or a combination of both techniques. • The pathology of 405 preoperative biopsies (239 metastatic site, 166 primary tumour) from 378 patients was reviewed at MDACC before cytoreductive nephrectomy. • The biopsy and nephrectomy specimens had the same histological subtype in 96.0% of clear-cell renal cell carcinomas (RCCs) and 72.7% of non-clear-cell RCCs. • Of 76 nephrectomy specimens where sarcomatoid de-differentiation was identified, only seven (9.2%) were able to be

  3. Diagnosis of Hepatocellular Carcinoma Complicating Liver Cirrhosis: Utility of Repeat Ultrasound-Guided Biopsy after Unsuccessful First Sampling

    SciTech Connect

    Caturelli, Eugenio; Biasini, Elisabetta; Bartolucci, Francesca; Facciorusso, Domenico; Decembrino, Francesco; Attino, Vito; Bisceglia, Michele

    2002-08-15

    Purpose: To evaluate the utility of a second ultrasound-guided fine-needle biopsy of liver nodules thought to be hepatocellular carcinoma when the original biopsy has failed to provide a reliable diagnosis. Methods: Thirty-seven cirrhotic patients underwent ultrasound-guided fine-needle biopsy of liver nodules that were subsequently diagnosed as hepatocellular carcinoma. Each biopsy involved a single puncture with a 20 G cutting needle, which yielded pathologic material used both for cytologic and histologic studies. In 23 cases (mean diameter of nodules 48 mm) the biopsy furnished exclusively necrotic material (non-diagnostic subgroup); in the other 14 cases (mean diameter 26 mm) the biopsy yielded no neoplastic elements (false-negative subgroup). All 37 nodules were subjected to repeat biopsies performed in the same manner. Results: The repeat biopsies provided a diagnosis of hepatocellular carcinoma in six of the 23 patients from the non-diagnostic subgroup and in seven of the 14 in the false-negative subgroup. Overall, repeat biopsy produced a diagnostic gain of 35.1%. Conclusion: The chance of success with repeat biopsy of hepatocellular carcinoma is limited and may depend to some extent on the characteristics of the lesions (i.e., areas of necrosis in large nodules, well-differentiated cellular populations in small ones)

  4. Comparison of computer-assisted brush biopsy results with follow up scalpel biopsy and histology.

    PubMed

    Svirsky, John A; Burns, James C; Carpenter, William M; Cohen, Donald M; Bhattacharyya, Indraneel; Fantasia, John E; Lederman, David A; Lynch, Denis P; Sciubba, James J; Zunt, Susan L

    2002-01-01

    Oral brush biopsy results were compared with scalpel biopsy and histology to determine the positive predictive value of an abnormal brush biopsy finding. Of 243 patients with abnormal brush biopsies, 93 proved positive for dysplasia (79) or carcinoma (14) and 150 were negative for either dysplasia or carcinoma. Therefore, the positive predictive value of an abnormal brush biopsy was 38% (93/243). By using the oral brush biopsy, dentists can inform their patients that abnormal findings have a strong positive predictive value for dysplasia or carcinoma and therefore require follow-up confirmation by scalpel biopsy.

  5. Prostate Biopsy for the Interventional Radiologist

    PubMed Central

    Hong, Cheng William; Amalou, Hayet; Xu, Sheng; Turkbey, Baris; Yan, Pingkun; Kruecker, Jochen; Pinto, Peter A; Choyke, Peter L; Wood, Bradford J

    2015-01-01

    Prostate biopsies are usually performed by urologists in the office setting using transrectal ultrasound (TRUS) guidance. The current standard of care involves obtaining 10–14 cores from different anatomical sections. These biopsies are usually not directed into a specific lesion as most prostate cancers are not visible on TRUS. Color-Doppler, ultrasound contrast agents, elastography, MRI, and MRI/ultrasound fusion are proposed as imaging methods to guide prostate biopsies. Prostate MRI and fusion biopsy create opportunities for diagnostic and interventional radiologists to play an increasingly important role in the screening, evaluation, diagnosis, targeted biopsy, surveillance and focal therapy of the prostate cancer patient. PMID:24581731

  6. Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice.

    PubMed

    Bayer, Kimberly

    2016-02-01

    Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds. The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse. A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping. Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation. There is a need to begin to look for populations for which delayed cord clamping can be implemented. Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.

  7. Randomised trial of cord clamping and initial stabilisation at very preterm birth.

    PubMed

    Duley, Lelia; Dorling, Jon; Pushpa-Rajah, Angela; Oddie, Sam J; Yoxall, Charles William; Schoonakker, Bernard; Bradshaw, Lucy; Mitchell, Eleanor J; Fawke, Joe Anthony

    2017-09-18

    For very preterm births, to compare alternative policies for umbilical cord clamping and immediate neonatal care. Parallel group randomised (1:1) trial, using sealed opaque numbered envelopes. Eight UK tertiary maternity units. 261 women expected to have a live birth before 32 weeks, and their 276 babies. Cord clamping after at least 2 min and immediate neonatal care with cord intact, or clamping within 20 s and immediate neonatal care after clamping. Intraventricular haemorrhage (IVH), death before discharge. 132 women (137 babies) were allocated clamping ≥2 min and neonatal care cord intact, and 129 (139) clamping ≤20 s and neonatal care after clamping; six mother-infant dyads were excluded (2, 4) as birth was after 35(+6) weeks, one withdrew (death data only available) (0, 1). Median gestation was 28.9 weeks for those allocated clamping ≥2 min, and 29.2 for those allocated clamping ≤20 s. Median time to clamping was 120 and 11 s, respectively. 7 of 135 infants (5.2%) allocated clamping ≥2 min died and 15 of 135 (11.1%) allocated clamping ≤20 s; risk difference (RD) -5.9% (95% CI -12.4% to 0.6%). Of live births, 43 of 134 (32%) had IVH vs 47 of 132 (36%), respectively; RD -3.5% (-14.9% to 7.8%). There were no clear differences in other outcomes for infants or mothers. This is promising evidence that clamping after at least 2 min and immediate neonatal care with cord intact at very preterm birth may improve outcome; a large trial is urgently needed. ISRCTN 21456601. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Cervical biopsy sampling variability in ALTS.

    PubMed

    Ferris, Daron G; Litaker, Mark S

    2011-04-01

    To determine histologic sampling variability among clinical center colposcopists and quality control reviewers in the Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion Triage Study. Clinical center colposcopists and quality control reviewers independently indicated need for biopsy, number of biopsies needed, and optimal biopsy location on customized computer software and digitized colposcopic images while examining subjects or monitoring colposcopists in the Atypical Squamous Cells of Undetermined Significance/Low-grade Squamous Intraepithelial Lesion Triage Study. Results were compared using percentages of agreement, κ statistics, McNemar, and paired t tests. Colposcopists and reviewers agreed whether a cervical biopsy was indicated for 2,631 (72.9%) of 3,610 evaluable subjects and 415 (91.6%) of 453 subjects with cervical intraepithelial neoplasia 2 or worse by histologic diagnosis. Only 3 of 41 colposcopists indicated 20% or greater of their biopsy sites to be more than 10 mm from reviewers' recommended sites. The mean of the greatest colposcopist-to-reviewer biopsy site distance was significantly greater than the mean maximum distance between reviewers' biopsy sites (14.9 vs 12.2 mm, p < .0001, respectively). Colposcopists indicated a significantly greater number of biopsy sites compared with consensus of reviewers (p < .0001). When cervical cancer precursors are present in women with minor cytologic abnormalities, most colposcopists obtain a biopsy. However, biopsy site placement can vary considerably. Only a minority of colposcopists sample significantly beyond recommended areas and less biopsy site variability occurs among experts.

  9. Voltage and Current Clamp Transients with Membrane Dielectric Loss

    PubMed Central

    Fitzhugh, R.; Cole, K. S.

    1973-01-01

    Transient responses of a space-clamped squid axon membrane to step changes of voltage or current are often approximated by exponential functions of time, corresponding to a series resistance and a membrane capacity of 1.0 μF/cm2. Curtis and Cole (1938, J. Gen. Physiol. 21:757) found, however, that the membrane had a constant phase angle impedance z = z1(jωτ)-α, with a mean α = 0.85. (α = 1.0 for an ideal capacitor; α < 1.0 may represent dielectric loss.) This result is supported by more recently published experimental data. For comparison with experiments, we have computed functions expressing voltage and current transients with constant phase angle capacitance, a parallel leakage conductance, and a series resistance, at nine values of α from 0.5 to 1.0. A series in powers of tα provided a good approximation for short times; one in powers of t-α, for long times; for intermediate times, a rational approximation matching both series for a finite number of terms was used. These computations may help in determining experimental series resistances and parallel leakage conductances from membrane voltage or current clamp data. PMID:4754194

  10. The human dynamic clamp as a paradigm for social interaction.

    PubMed

    Dumas, Guillaume; de Guzman, Gonzalo C; Tognoli, Emmanuelle; Kelso, J A Scott

    2014-09-02

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject's own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual "teacher." We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof.

  11. Image processing techniques in computer-assisted patch clamping

    NASA Astrophysics Data System (ADS)

    Azizian, Mahdi; Patel, Rajni; Gavrilovici, Cezar; Poulter, Michael O.

    2010-02-01

    Patch clamping is used in electrophysiology to study single or multiple ion channels in cells. Multiple micropipettes are used as electrodes to collect data from several cells. Placement of these electrodes is a time consuming and complicated task due to the lack of depth perception, limited view through the microscope lens and the possibility of collisions between micro-pipettes. To aid in this process, a computer-assisted approach is developed using image processing techniques applied to images obtained through the microscope. Image processing algorithms are applied to perform autofocusing, relative depth estimation, distance estimation and tracking of the micro-pipettes in the images without making any major changes in the existing patch clamp equipment. An autofocusing algorithm with a micrometer precision is developed and the relative depth estimation is performed based on autofocusing. A micro-pipette tip detection algorithm is developed which can be used to initialize or reset the tracking algorithm and to calibrate the system by registering the relative image and micro-manipulator coordinates. An image-based tracking algorithm is also developed to track a micro-pipette tip in real time. The real-time tracking data is then used for visual servoing the micro-pipette tips and updating the calibration information.

  12. Binding inhibitors of the bacterial sliding clamp by design.

    PubMed

    Wijffels, Gene; Johnson, Wynona M; Oakley, Aaron J; Turner, Kathleen; Epa, V Chandana; Briscoe, Susan J; Polley, Mitchell; Liepa, Andris J; Hofmann, Albert; Buchardt, Jens; Christensen, Caspar; Prosselkov, Pavel; Dalrymple, Brian P; Alewood, Paul F; Jennings, Philip A; Dixon, Nicholas E; Winkler, David A

    2011-07-14

    The bacterial replisome is a target for the development of new antibiotics to combat drug resistant strains. The β(2) sliding clamp is an essential component of the replicative machinery, providing a platform for recruitment and function of other replisomal components and ensuring polymerase processivity during DNA replication and repair. A single binding region of the clamp is utilized by its binding partners, which all contain conserved binding motifs. The C-terminal Leu and Phe residues of these motifs are integral to the binding interaction. We acquired three-dimensional structural information on the binding site in β(2) by a study of the binding of modified peptides. Development of a three-dimensional pharmacophore based on the C-terminal dipeptide of the motif enabled identification of compounds that on further development inhibited α-β(2) interaction at low micromolar concentrations. We report the crystal structure of the complex containing one of these inhibitors, a biphenyl oxime, bound to β(2), as a starting point for further inhibitor design.

  13. Umbilical cord clamping and preterm infants: a randomised trial.

    PubMed Central

    Kinmond, S; Aitchison, T C; Holland, B M; Jones, J G; Turner, T L; Wardrop, C A

    1993-01-01

    OBJECTIVE--To investigate the clinical effects of regulating umbilical cord clamping in preterm infants. DESIGN--A prospective randomised study. SETTING--The Queen Mother's Hospital, Glasgow. SUBJECTS--36 vaginally delivered infants over 27 and under 33 weeks' gestation. INTERVENTION--Holding the infant 20 cm below the introitus for 30 seconds before clamping the umbilical cord ("regulated" group, 17 patients), or conventional management ("random" group, 19 patients). MAIN OUTCOME MEASURES--Initial packed cell volume, peak serum bilirubin concentrations, red cell transfusion requirements, and respiratory impairment (assessed by ventilatory requirements, arterial-alveolar oxygen tension ratio over the first day in ventilated infants, and duration of dependence on supplemental oxygen). RESULTS--There were statistically significant differences between the two groups in mean initial packed cell volume (regulated group 0.564, random group 0.509) and median red cell transfusion requirements (regulated group zero, random group 23 ml/kg). 13 infants from each group underwent mechanical ventilation and showed significant differences in mean minimum arterial-alveolar oxygen tension ratio on the first day (regulated group 0.42, random group 0.22) and in median duration of dependence on supplemental oxygen (regulated group three days, random group 10 days). Differences in final outcome measures such as duration of supplemental oxygen dependence and red cell transfusion requirements were mediated primarily through arterial-alveolar oxygen tension ratio and also packed cell volume. CONCLUSIONS--This intervention at preterm deliveries produces clinical and economic benefits. PMID:8443480

  14. Clamping of fine Kirschner wires in external fixators.

    PubMed

    Zamani, Ahmad R; Oyadiji, S Olutunde

    2016-11-01

    In Ilizarov circular (ring) external fixators, fine Kirschner wires are used to fix the bone to the fixator. Clamping of the wires to the rings with different bolt torques has been studied. However, the relation between the bolt torque and the fixation load applied to the wire was not investigated. In this work, finite element method is used to address this problem. Here, a fully three-dimensional model of the wire fixation assembly was built, with geometric details like threads on the bolt to produce a realistic simulation of the clamping of the wire. Both cannulated and slotted bolt types were studied and values of 0.2, 0.25, 0.3 and 0.45 were used for coefficient of friction. A torque was applied to the nut while the ring section and bolt kept in place. The results for bolt load, nut rotation as well as axial and radial wire deformations were obtained. The results demonstrated a linear relation between the bolt load and the bolt torque. The coefficient of this relationship was shown to be inversely proportional to the coefficient of friction. For all results, the bolt load (N) was approximately 124 times the bolt torque (N m) divided by the friction coefficient. The results highlighted the difference between the cannulated and the slotted bolts in terms of their grip on the wire.

  15. Prostate biopsy volume predicts final tumor volume.

    PubMed

    Zavaski, Michael E; Korus, Adam; Staff, Ilene; Champagne, Alison; Fish-Furhman, Jamie; Tortora, Joseph; Meraney, Anoop; Kesler, Stuart; Wagner, Joseph

    2014-03-01

    To assess the ability of prostate biopsy volume to effectively predict actual tumor volume, and whether increasing the number of prostate biopsy cores improves the ability to forecast actual tumor volume. 765 patients who underwent robotic radical prostatectomy (2009-2010) were identified. Of these, 663 had complete demographics, biopsy, and final pathology data available. The number ofbiopsy samples, biopsy tumor volume, and actual tumor volume were calculated from pathology reports. Data from 663 radical prostatectomy specimens indicated a positive linearrelationship between biopsy tumor volume and actual tumor volume (R=0.524, P< 0.0001). The number ofbiopsy samples collected (i.e., < or =6, 7-8, 9-10, 11-12, 13-14, or > or =15) did not affect the ability of biopsy tumor volume to predict final tumor volume. The routine collection of biopsy tumor volume may prove useful in predicting actual tumor volume and the construction of more effective preoperative nomograms.

  16. Semiautomatic core biopsy. A modified biopsy technique in breast diseases.

    PubMed

    Abdsaleh, S; Azavedo, E; Lindgren, P G

    2003-01-01

    To evaluate a semiautomatic gun to retrieve diagnostic core specimens of lesions in the breast and the axillary region. In a series of 180 consecutive core biopsies (2.1 mm), 145 (142 breasts and 3 axillae) were performed with a semiautomatic gun (18 stereotaxic and 127 US-guided) from lesions presenting mammographically as microcalcifications (n = 15) and opacities (n = 130). The gun did not work satisfactorily in 34 lesions, which were tumors with a very hard consistency. One additional patient was excluded because of technical failure. Biopsy diagnoses in the 145 patients were correlated to surgical histopathology, follow-up mammograms and/or clinical findings. Histologic examination of the specimens resulted in correct diagnoses in 89% (129/145) of the total material and in 87% (108/124) of cancers. In 107 cases, in which only 1 specimen was obtained, 83 of 89 cancers (87%) were detected. Length of specimens ranged from 3 mm (n = 2) to 17 mm (n = 31). Among patients with a 17-mm-long specimen, there was only 1 false-negative diagnosis. The semiautomatic gun provided diagnostic specimens in a majority of cases and could be used as an alternative to the automatic guns when size or location of the lesions necessitates a high precision. It was not suitable for use in very hard tumors.

  17. Does length of prostate biopsy cores have an impact on diagnosis of prostate cancer?

    PubMed Central

    Ergün, Müslüm; İslamoğlu, Ekrem; Yalçınkaya, Soner; Tokgöz, Hüsnü; Savaş, Murat

    2016-01-01

    Objective To investigate whether core length is a significant biopsy parameter in the detection of prostate cancer. Material and methods We retrospectively analyzed pathology reports of the specimens of 188 patients diagnosed with prostate cancer who had undergone initial transrectal ultrasound (TRUS) guided prostate biopsy, and compared biopsy core lengths of the patients with, and without prostate cancer. The biopsy specimens of prostate cancer patients were divided into 3 groups according to core length, and the data obtained were compared (Group 1; total core length <10 mm, Group 2; total core length 10 mm–19 mm, and Group 3; total core length >20 mm). Biopsy core lengths of the patients diagnosed as prostate cancer, and benign prostatic hyperplasia were compared, and a certain cut-off value for core length with optimal diagnostic sensitivity and specificity for prostate cancer was calculated. Results Mean age, PSA and total length of cores were 65.08±7.41 years, 9.82±6.34 ng/mL and 11.2±0.2 mm, respectively. Assessment of biopsy core lengths showed that cores with cancer (n=993, median length 12.5 mm) were significantly longer than benign cores (n=1185, median length=11.3 mm) (p<0.001). Core length analysis yielded 12 mm cores have an optimal sensitivity (41.9%) and specificity (62%) for detection of cancer (odds ratio: 1.08). Conclusion Biopsy core length is one of the most important parameter that determines the quality of biopsy and detection of prostate cancer. A median sample length of 12 mm is ideal lower limit for cancer detection, and biopsy procedures which yield shorter biopsy cores should be repeated. PMID:27635285

  18. Methylation analyses in liquid biopsy

    PubMed Central

    Lissa, Delphine

    2016-01-01

    Lung cancer is the leading cause of cancer-related deaths worldwide. Recent implementation of low-dose computed tomography (LDCT) screening is predicted to lead to diagnosis of lung cancer at an earlier stage, with survival benefit. However, there is still a pressing need for biomarkers that will identify individuals eligible for screening, as well as improve the diagnostic accuracy of LDCT. In addition, biomarkers for prognostic stratification of patients with early stage disease, and those that can be used as surrogates to monitor tumor evolution, will greatly improve clinical management. Molecular alterations found in the DNA of tumor cells, such as mutations, translocations and methylation, are reflected in DNA that is released from the tumor into the bloodstream. Thus, in recent years, circulating tumor DNA (ctDNA) has gained increasing attention as a noninvasive alternative to tissue biopsies and potential surrogate for the entire tumor genome. Activating gene mutations found in ctDNA have been proven effective in predicting response to targeted therapy. Analysis of ctDNA is also a valuable tool for longitudinal follow-up of cancer patients that does not require serial biopsies and may anticipate the acquisition of resistance. DNA methylation has also emerged as a promising marker for early detection, prognosis and real-time follow-up of tumor dynamics that is independent of the genomic composition of the primary tumor. This review summarizes the various investigational applications of methylated ctDNA in lung cancer reported to date. It also provides a brief overview of the technologies for analysis of DNA methylation in liquid biopsies, and the challenges that befall the implementation of methylated ctDNA into routine clinical practice. PMID:27826530

  19. Thoracoscopic lung biopsy in 285 patients with diffuse pulmonary disease.

    PubMed

    Samejima, Joji; Tajiri, Michihiko; Ogura, Takashi; Baba, Tomohisa; Omori, Takahiro; Tsuboi, Masahiro; Masuda, Munetaka

    2015-02-01

    Surgical lung biopsy is generally considered the most appropriate method for diagnosing diffuse lung disease. However, there are few reports focusing on only one thoracoscopic technique. This study was designed to determine the morbidity and mortality related to video-assisted thoracoscopic lung biopsy in a single center, thereby providing data on the severity of morbidity and clarifying the risk factors. We analyzed 285 patients with undiagnosed diffuse lung disease who underwent video-assisted thoracoscopic lung biopsy at Kanagawa Cardiovascular and Respiratory Center from February 2007 to April 2012. We recorded the severity of postoperative complications using the Clavien-Dindo classification. The surgical morbidity was 7.0% (20/285), including delayed pulmonary fistulas in 11 patients, acute exacerbation in 3, prolonged air leakage (>7 days) in 2, hypoxemia in 2, atrial fibrillation in 1, and premature ventricular contraction in 1. Based on the Clavien-Dindo classification, grade I, II, IIIa, IIIb, and IVa complications accounted for 20%, 10%, 50%, 5%, and 15%, respectively. The 30-day mortality was 0%. The diagnostic yield was 100%. Although acute exacerbation occurred in 2 patients with idiopathic pulmonary fibrosis and 1 with fibrotic nonspecific interstitial pneumonia, there were no distinctive features that allowed preoperative prediction of acute exacerbation. Our findings indicate that video-assisted thoracoscopic lung biopsy is a feasible procedure. We hope to clarify risk factors in future research. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  20. Nondiagnostic conjunctival map biopsies for sebaceous carcinoma.

    PubMed

    Koreen, Irina V; Flint, Andrew; Nelson, Christine C; Frueh, Bartley R; Elner, Victor M

    2009-08-01

    To compare the prevalence of nondiagnostic conjunctival map biopsies in patients with extensive pagetoid sebaceous carcinoma (defined as involvement of 3 or 4 quadrants of the ocular surface) and in patients without extensive pagetoid tumor (defined as involvement of 1 or 2 quadrants of the ocular surface). Retrospective medical record and pathologic specimen review of 20 patients treated for sebaceous carcinoma at a tertiary care center. Biopsies with artifactual loss of or damage to the epithelium were categorized as nondiagnostic. One hundred forty-four map biopsies were reviewed, an average of 7.2 (standard deviation [SD], 4.4) biopsies per patient. Sixteen patients had extensive pagetoid tumor, 4 did not. Fifteen percent of biopsies were nondiagnostic. The frequency of nondiagnostic biopsies in patients with and without extensive pagetoid tumor was 37% and 10%, respectively. The odds ratio of nondiagnostic biopsy in the setting of extensive pagetoid tumor was 5.9 (95% confidence interval, 2.3-15.6; P = .004). Six of the sixteen patients (38%) without extensive pagetoid tumor had at least 1 nondiagnostic biopsy, with an average of 1.8 (SD, 1.6) nondiagnostic biopsies per patient (22% of biopsies). Two of the 4 patients (50%) with extensive pagetoid tumor had at least 1 nondiagnostic biopsy, with an average of 5.5 (SD, 3.5) nondiagnostic biopsies per patient (57% of biopsies). Nondiagnostic, de-epithelialized conjunctival map biopsies are more common in patients with extensive pagetoid tumor than in those with limited or no pagetoid tumor. Artifactual epithelial loss may result from disruption of epithelial adhesion to the basement membrane by infiltrating tumor cells.

  1. Comparison of sonoelastography guided biopsy with systematic biopsy: impact on prostate cancer detection.

    PubMed

    Pallwein, Leo; Mitterberger, Michael; Struve, Peter; Horninger, Wolfgang; Aigner, Friedrich; Bartsch, Georg; Gradl, Johann; Schurich, Matthias; Pedross, Florian; Frauscher, Ferdinand

    2007-09-01

    A prospective study was performed to determine the value of sonoelastography (SE) targeted biopsy for prostate cancer (PCa) detection. A series of 230 male screening volunteers was examined. Two independent examiners evaluated each subject. One single investigator performed < or =5 SE targeted biopsies into suspicious regions in the peripheral zone only. The stiffness of the lesion was displayed by SE and color-coded from red (soft) to blue (hard). Hard lesions were considered as malignant and targeted by biopsy. Subsequently, another examiner performed ten systematic biopsies. Cancer detection rates of the two techniques were compared. Cancer was detected in 81 of the 230 patients (35%), including 68 (30%) by SE targeted biopsy and in 58 (25%) by systematic biopsy. Cancer was detected by targeted biopsy alone in 23 patients (10%) and by systematic biopsy alone in 13 patients (6%). The detection rate for SE targeted biopsy cores (12.7% or 135 of 1,109 cores) was significantly better than for systematic biopsy cores (5.6% or 130 of 2,300 cores, P < 0.001). SE targeted biopsy in a patient with cancer was 2.9-fold more likely to detect PCa than systematic biopsy. SE targeted biopsy detected more cases of PCa than systematic biopsy, with fewer than half the number of biopsy cores in this prostate-specific antigen screening population.

  2. Transjugular Renal Biopsy: Our Experience and Technical Considerations

    SciTech Connect

    See, Teik Choon; Thompson, Barbara C.; Howie, Alexander J.; Karamshi, M.; Papadopoulou, Anthie M.; Davies, Neil; Tibballs, Jonathan

    2008-09-15

    The purpose of this study was to describe the indications for and technique of transjugular renal biopsy (TJRB) and evaluate the efficacy and complications of this method. We performed a retrospective review of 59 patients who underwent TJRB using the Quick-core needle biopsy system (Cook, Letchworth, UK) over a 4-year period. The indications for obtaining renal biopsy included acute renal failure, chronic renal failure, nephrotic syndrome, and proteinuria with or without other associated disease. Indications for the transjugular approach included coagulopathy, biopsy of a solitary kidney or essentially single functioning kidney, simultaneous renal and hepatic biopsy, morbid obesity, and failed percutaneous biopsy. All but four cases were performed via the right internal jugular vein. The right, left, or both renal veins were cannulated in 41, 14, and 4 cases, respectively. Combined liver and renal biopsies were obtained in seven cases. Diagnostic biopsy specimens were obtained in 56 of 59 patients (95%). The number and size of tissue cores ranged from 1 to 9 mm and from 1 to 20 mm, respectively. The mean numbers of glomeruli per procedure on light microscopy and electron microscopy were 10.3 and 2.6, respectively. Specimens for immunohistology were acquired in 49 cases, of which 40 were adequate. Of the 56 successful TJRB procedures, 34 (61%) were associated with isolated capsular perforation (19), contained subcapsular leak (10), isolated collecting system puncture (1), and concurrent collecting system and capsular perforation (4). There was a significant increase in capsular perforation with six or more needle passes, although no significant correlation was seen between number of needle passes and complication. Six patients had minor complications defined as hematuria or loin pain. Seven patients developed major complications, of whom five received blood transfusion alone. Two required intervention: in one an arteriocalyceal fistula was embolized and the patient

  3. Comparison of bronchial washing, brushing and biopsy for diagnosis of pulmonary tuberculosis.

    PubMed

    Palenque, E; Amor, E; Bernaldo de Quiros, J C

    1987-04-01

    The diagnostic yields of bronchial washings, bronchial brushings and lung biopsy specimens were compared in 50 patients with positive Mycobacterium tuberculosis cultures. The number of positive results obtained with cultures of bronchial brushings was significantly higher than that with bronchial washings (p less than 0.001). The histological study of biopsy lung material improved the rate of immediate or rapid diagnosis of tuberculosis (p less than 0.001).

  4. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes.

    PubMed

    McDonald, Susan J; Middleton, Philippa

    2008-04-16

    Policies for timing of cord clamping vary, with early cord clamping generally carried out in the first 60 seconds after birth, whereas later cord clamping usually involves clamping the umbilical cord greater than one minute after the birth or when cord pulsation has ceased. To determine the effects of different policies of timing of cord clamping at delivery of the placenta on maternal and neonatal outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (December 2007). Randomised controlled trials comparing early and late cord clamping. Two review authors independently assessed trial eligibility and quality and extracted data. We included 11 trials of 2989 mothers and their babies. No significant differences between early and late cord clamping were seen for postpartum haemorrhage or severe postpartum haemorrhage in any of the five trials (2236 women) which measured this outcome (relative risk (RR) for postpartum haemorrhage 500 mls or more 1.22, 95% confidence interval (CI) 0.96 to 1.55). For neonatal outcomes, our review showed both benefits and harms for late cord clamping. Following birth, there was a significant increase in infants needing phototherapy for jaundice (RR 0.59, 95% CI 0.38 to 0.92; five trials of 1762 infants) in the late compared with early clamping group. This was accompanied by significant increases in newborn haemoglobin levels in the late cord clamping group compared with early cord clamping (weighted mean difference 2.17 g/dL; 95% CI 0.28 to 4.06; three trials of 671 infants), although this effect did not persist past six months. Infant ferritin levels remained higher in the late clamping group than the early clamping group at six months. One definition of active management includes directions to administer an uterotonic with birth of the anterior shoulder of the baby and to clamp the umbilical cord within 30-60 seconds of birth of the baby (which is not always feasible in practice). In this review delaying

  5. Real time intra-procedural 18F-FDG PET/CT guided biopsy using automated robotic biopsy arm (ARA) in the evaluation of thoracic lesions with prior inconclusive biopsy results.

    PubMed

    Radhakrishnan, Renjith Kalathoorakathu; Mittal, Bhagwant Rai; Gorla, Arun Kumar Reddy; Basher, Rajender Kumar; Sood, Ashwani; Bal, Amanjit; Kalra, Naveen; Khandelwal, Niranjan; Singh, Navneet; Behera, Digambar

    2017-09-20

    The aim of this study was to assess the feasibility and appraise the diagnostic utility of real time 18F-FDG PET/CT guided biopsy under automated robotic biopsy arm (ARA) guidance for the evaluation of thoracic lesions with prior inconclusive biopsy results. PET/CT guided biopsy of thoracic lesions was performed in patients who had at least one previous inconclusive biopsy. A total of 25 patients (Male: Female- 18 males, 7 females; Age: Range- 13-75; mean- 53.7) were included in this study. All these patients underwent percutaneous needle biopsies under real time PET/CT guidance using ARA (ROBIO-EX, Perfint healthcare Pvt Ltd, Chennai, India) needle navigation technique. Histopathology and clinical follow up results were reviewed for assessing the accuracy of procedures. Adequate representative tissue sample could be retrieved in all the patients. No major procedure related complications were encountered in any patient. Of the twenty five procedures, 21 lesions were positive for malignancy and benign findings were observed in the other 4 lesions on histopathology. None of the patients required further biopsy in arriving at a final diagnosis. Overall diagnostic yield of the procedure was 100%. Real time 18F-FDG PET/CT guidance for percutaneous biopsies of lung and mediastinal lesions is a feasible technique with potential utility in patients with previous inconclusive biopsy results. Advances in knowledge: 18F-FDG PET/CT guidance reduces the sampling errors by specifically targeting areas of viability and avoiding necrosis/ atelectasis. A navigational tool like ARA is thought to help in accurately targeting these areas.

  6. Relationship of Pre-biopsy Multiparametric MRI and Biopsy Indication with MRI-US Fusion-Targeted Prostate Biopsy Outcomes

    PubMed Central

    Meng, Xiaosong; Rosenkrantz, Andrew B.; Mendhiratta, Neil; Fenstermaker, Michael; Huang, Richard; Wysock, James S.; Bjurlin, Marc; Marshall, Susan; Deng, Fang-Ming; Zhou, Ming; Melamed, Jonathan; Huang, William C.; Lepor, Herbert; Taneja, Samir S.

    2016-01-01

    BACKGROUND Increasing evidence supports the use of MRI-ultrasound fusion-targeted prostate biopsy (MRF-TB) to improve the detection of clinically significant prostate cancer (PCa) while limiting detection of indolent disease compared to systematic 12-core biopsy (SB). OBJECTIVE We report results of MRF-TB and SB and the relationship between biopsy outcomes and pre-biopsy MRI in 601 men presenting to our center. DESIGN/SETTING/PARTICIPANTS Retrospective analysis of a prospectively acquired cohort of men presenting for prostate biopsy over a 26-month period. A total of 601 of 803 consecutively eligible men were included. INTERVENTIONS All men were offered pre-biopsy MRI and assigned a maximum MRI suspicion score (mSS). Men with an MRI abnormality underwent combined MRF-TB and SB. OUTCOMES Detection rate of all PCa and high-grade PCa (Gleason score (GS)≥7) were compared by McNemar's test. RESULTS MRF-TB detected fewer GS6 PCa (75 vs 121, p<0.001) and more GS≥7 PCa (158 vs 117, p<0.001) than SB. Increasing mSS was associated with increasing detection of GS≥7 PCa (p<0.001), but had no relationship to the detection of GS6 PCa. The prediction of GS≥7 disease by mSS varied according to biopsy history. Compared to SB, MRF-TB identified more GS≥7 cancer in men with no prior biopsy (88 vs 72, p=0.012), with prior negative biopsy (28 vs 16, p=0.010), and with prior cancer diagnosis (42 vs 29, p=0.043). MRF-TB detected fewer GS6 cancers in men with no prior biopsy (32 vs 60, p<.001) and prior cancer (30 vs 46, p=0.034). Limitations include retrospective design and potential for selection bias given a referral population. CONCLUSIONS MRI-US fusion-targeted biopsy detects more high-grade cancer than systematic biopsy while limiting detection of GS6 cancer in men presenting for prostate biopsy. These findings suggest that pre-biopsy mpMRI and MRF-TB should be considered in all men undergoing prostate biopsy and, in conjunction with biopsy indication, mSS may ultimately

  7. Optimal timing of umbilical cord clamping for term and preterm babies.

    PubMed

    Duley, Lelia; Batey, Natalie

    2013-11-01

    Deferring cord clamping allows blood flow between baby and placenta to continue for a few moments. This often leads to increased neonatal blood volume at birth. It also allows for longer transition to the neonatal circulation. Optimal timing for clamping the cord remains uncertain. This paper discusses the physiology of placental transfusion and presents the evidence from systematic reviews of randomised trials comparing alternative strategies for cord clamping for both term and preterm births. For healthy term infants, deferring cord clamping increases iron stores in infancy. Therefore, a more liberal approach to deferring cord clamping appears to be warranted, provided screening and treatment for jaundice requiring phototherapy is available. For preterm births, although there are few data on the main clinical outcomes, the evidence is promising that deferred cord clamping may be beneficial. For both term and preterm infants there is little information about long term development. © 2013.

  8. CT-Guided Biopsy of Small Liver Lesions: Visibility, Artifacts, and Corresponding Diagnostic Accuracy

    SciTech Connect

    Stattaus, Joerg Kuehl, Hilmar; Ladd, Susanne; Schroeder, Tobias; Antoch, Gerald; Baba, Hideo A.; Barkhausen, Joerg; Forsting, Michael

    2007-09-15

    Purpose. Our study aimed to determine the visibility of small liver lesions during CT-guided biopsy and to assess the influence of lesion visibility on biopsy results. Material and Methods. Fifty patients underwent CT-guided core biopsy of small focal liver lesions (maximum diameter, 3 cm); 38 biopsies were performed using noncontrast CT, and the remaining 12 were contrast-enhanced. Visibility of all lesions was graded on a 4-point-scale (0 = not visible, 1 = poorly visible, 2 = sufficiently visible, 3 = excellently visible) before and during biopsy (with the needle placed adjacent to and within the target lesion). Results. Forty-three biopsies (86%) yielded diagnostic results, and seven biopsies were false-negative. In noncontrast biopsies, the rate of insufficiently visualized lesions (grades 0-1) increased significantly during the procedure, from 10.5% to 44.7%, due to needle artifacts. This resulted in more (17.6%) false-negative biopsy results compared to lesions with good visualization (4.8%), although this difference lacks statistical significance. Visualization impairment appeared more often with an intercostal or subcostal vs. an epigastric access and with a subcapsular vs. a central lesion location, respectively. With contrast-enhanced biopsy the visibility of hepatic lesions was only temporarily improved, with a risk of complete obscuration in the late phase. Conclusion. In conclusion, visibility of small liver lesions diminished significantly during CT-guided biopsy due to needle artifacts, with a fourfold increased rate of insufficiently visualized lesions and of false-negative histological results. Contrast enhancement did not reveal better results.

  9. Gallium-67 imaging in patients with dilated cardiomyopathy and biopsy-proven myocarditis

    SciTech Connect

    O'Connell, J.B.; Henkin, R.E.; Robinson, J.A.; Subramanian, R.; Scanlon, P.J.; Gunnar, R.M.

    1984-07-01

    Current standards for detection of myocarditis in a clinical setting rely on endomyocardial biopsy for accurate diagnosis. With this technique a subset of patients with dilated cardiomyopathy show unsuspected myocarditis histologically. Endomyocardial biopsy, despite its specificity, may lack sensitivity due to sampling error if the inflammation is patchy or focal. Therefore, inflammation-sensitive radioisotopic imaging may be a useful adjunct in the diagnosis of myocarditis. This study was designed to evaluate the applicability of gallium-67 (67Ga) myocardial imaging as an adjunct to endomyocardial biopsy in the diagnosis of myocarditis. Sixty-eight consecutive patients referred for evaluation of dilated cardiomyopathy underwent 71 parallel studies with 67Ga imaging and biopsies that served as the basis of comparison for this study. Histologic myocarditis was identified in 8% of biopsy specimens. Clinical and hemodynamic parameters could not be used to predict the presence of myocarditis. Five of six biopsy samples (87%) with myocarditis showed dense 67Ga uptake, whereas only nine of 65 negative biopsy samples (14%) were paired with equivocally positive 67Ga scans. The single patient with myocarditis and no myocardial 67Ga uptake had dense mediastinal lymph node uptake that may have obscured cardiac uptake. The incidence of myocarditis on biopsy with a positive 67Ga scan was 36% (5/14); however, the incidence of myocarditis with a negative 67Ga scan was only 1.8% (1/57). Follow-up scans for three patients showed close correlation of 67Ga uptake with myocarditis on biopsy. In conclusion 67Ga may be a useful screening test for identifying patients with a high yield of myocarditis on biopsy, and serial scans may eliminate the need for frequent biopsies in patients with proven myocarditis.

  10. [Transrectal biopsy scheme can predict incorrect histological grading in prostate cancer].

    PubMed

    Nieto-Morales, M L; Fernández-Ramos, J; Pérez-Méndez, L; Alventosa-Fernández, E; Pastor-Santoveña, M S; Aguirre-Jaime, A

    2014-01-01

    To identify factors that might explain why a prostate with a Gleason score (GS) <7 in the biopsy specimen can turn out to have a GS ≥7 in the surgical specimen. We compared the GS of biopsy specimens with the GS of surgical specimens in 185 patients who underwent surgery for prostate cancer. We calculated the sensitivity, specificity, and predictive values for the GS of the biopsy specimens. We used Cohen's kappa to determine the degree of concordance between a GS of <7 and ≥7 for the biopsy specimen and the surgical specimen. Age, a family history of prostate cancer, total prostate-specific antigen (tPSA), digital rectal examination, prostate structure and volume, and the number of biopsy cores (biopsy scheme) were analyzed using multivariable logistic regression. Histological study of biopsy specimens yielded high sensitivity (98%) but low specificity (49%) for GS ≤6 and low sensitivity (35, 26%) and high specificity (93, 99%) for GS=7 and GS ≥7, respectively. Cohen's kappa for the GS from the biopsy and surgical specimens was 0.43 (95% CI=30-56%). The biopsy scheme was the only predictor of discordance in the GS between the two techniques. Among the other variables included in the model, only tPSA showed a slightly significant association. Taking a scheme with less than 7 cores as a reference, we found no difference with 8 to 9 cores but we did find a difference with 10 to 11 cores and with 12 or more cores, with a prevalence ratio of 0.138 (95% CI=0.030-0.513) and 0.277 (95% CI=0.091-0.806), respectively. The GS of the biopsy depends on the scheme. This factor must be taken into account when choosing a treatment option in patients with low tumor grade in biopsy specimens. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  11. A Novel Technique to Improve the Processing of Minute Ureteroscopic Biopsies.

    PubMed

    Golan, Shay; Gerber, Glenn; Margel, David; Rath-Wolfson, Lea; Ehrlich, Yaron; Koren, Rumelia; Lifshitz, David

    2017-04-03

    To examine the ability of a new specimen handling technique to improve histopathological yield of ureteroscopic biopsies, performed in patients with suspected upper tract urothelial carcinoma (UTUC). In a bi-center retrospective study we compared the results of the new tissue handling technique (group 1) with the standard technique (group 2). In the new technique, to achieve maximal tissue preservation, the specimen is mounted on filter paper prior to embedding in paraffin. Multivariate analysis was performed to determine which factors are associated with optimal histological results. We further compared the biopsies with the final specimen in a subgroup of patients who underwent nephroureterectomy (NU). Of 55 ureteroscopic biopsies, 1 biopsy from group 1 (new technique) and 3 biopsies from group 2 (standard technique) were inadequate for pathological examination. 51 UTUC specimens were analyzed. Tumor grade and stage were determined in 85% and 63% of the patients in group 1 and in 83% and 25% of group 2 (p=0.85 and p=0.007). Orientation was preserved in 82% of group 1 and 42% of group 2 (p=0.003). On multivariate analysis biopsy technique and biopsy diameter were found to predict stage determination (p=0.01 and p=0.007) and tissue orientation (p=0.005 and p=0.04). Among patients who underwent NU, stage concordance between the biopsy and final pathology was observed in 56% and 27% of the patients in group 1 and 2, respectively. The new processing technique for small UTUC forceps biopsies decreases the rate of biopsies with insufficient material and improves biopsy interpretation.

  12. Fluorescence guidance during stereotactic biopsy

    NASA Astrophysics Data System (ADS)

    Stepp, Herbert; Beyer, Wolfgang; Brucker, David; Ehrhardt, Andre; Fischer, Stefan; Goebel, Werner; Goetz, Marcus; Guenther, Bettina; Hennig, Georg; Herms, Jochen; Irion, Klaus-Martin; Johansson, Ann; Kienast, Yvonne; Kniebuehler, Gesa; Li, Pan; Ruehm, Adrian; Sandner, Sabine

    2012-02-01

    Objective: When a stereotactic biopsy is taken to enable histopathological diagnosis of a suspected brain tumor, it is essential to i) do this safely, that is not injure a major blood vessel and ii) to obtain relevant vital material from the tumor. We are investigating the suitability of Indocyanine Green (ICG) fluorescence for blood vessel recognition and 5- Aminolevulinic acid (5-ALA) induced Protoporphyrin IX (PpIX) fluorescence for identification of proliferative brain tumor tissue. Methods: A fiber-optic endoscopic approach was studied to generate and detect both fluorescence signals. PpIX concentrations in brain tumors have been measured by chemical extraction. Preliminary equipment was studied in a mouse model. Results: PpIX-concentrations in glioblastoma tissue showed high inner- and inter-patient variability, but each patient out of 15 with interpretable data showed at least one sample with a PpIX-concentration exceeding 2.4 μmol/l, which is easily detectable by state-of-the-art fiberoptic fluorescence spectroscopy and imaging. The imaging fluoroscope with 30,000 pixels resolution could be introduced through a position controlled stereotactic needle. ICG-fluorescence from vessels with diameters >= 0.1 mm can be detected with a contrast of 2-2.5 against surrounding tissue. Conclusion: Fluorescence detection during stereotactic biopsy might increase safety and precision of the procedure significantly.

  13. Axillary lymph node core biopsy for breast cancer metastases -- how many needle passes are enough?

    PubMed

    Macaskill, E J; Purdie, C A; Jordan, L B; Mclean, D; Whelehan, P; Brown, D C; Evans, A

    2012-05-01

    To determine the diagnostic yield of each of three core passes when sampling abnormal lymph nodes in patients presenting with breast cancer. All patients suspected of having breast cancer had axillary ultrasound as part of initial assessment. Radiologically abnormal nodes (cortical thickness >2.3mm or round shape) were biopsied with three passes of a 22 mm throw 14 G core biopsy needle and sent for histopathology in separate numbered pots. Data were collected prospectively, and analysis performed on the data of 55 consecutive patients who had positive nodes on at least one core biopsy needle pass. Of 55 patients with a positive node on core biopsy, tumour was noted in all three cores taken in 39 (70.9%). Lymph node metastasis was detected in 45 (81.8%) first core biopsies. With the first two cores taken, positive results were detected in 53 of 55 cases (96.4%). In both cases where tumour was only found on a third core biopsy pass, no lymph node tissue was present in the first two biopsy passes. Two well-directed 14 G core biopsy samples from an abnormal axillary node are adequate for diagnosis of breast cancer metastasis. Copyright © 2011 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  14. Liver biopsies in the acquired immune deficiency syndrome: influence of endemic disease and drug abuse.

    PubMed

    Comer, G M; Mukherjee, S; Scholes, J V; Holness, L G; Clain, D J

    1989-12-01

    A retrospective review of 48 liver biopsies in 34 patients with acquired immune deficiency syndrome (AIDS) and 10 patients with AIDS-related complex (ARC) was performed at Harlem Hospital Center to assess the diagnostic yield of liver biopsies in this distinct patient population. Among the patients, 93.2% were black and 32 were males, with a mean age of 36.7 yr. Intravenous drug abuse was a risk factor for AIDS in 81.8% of patients. Liver biopsies were particularly useful in patients with fever of unclear origin, which was positively correlated with the presence of granulomas (p = 0.01). Granulomas due to mycobacteria were present in 16 (33.3%) of the biopsies. Liver biopsy proved to be clinically significant in 14 of 17 patients (82.3%) with mycobacterial disease, or 29.3% of the liver biopsies. Chronic active hepatitis was present in 12 (29.2%) of the biopsies, and in all but one was due to non-A non-B hepatitis viruses. All patients with chronic active hepatitis were intravenous drug abusers or the sexual partners of intravenous drug abusers. Liver biopsy can provide important diagnostic information in AIDS patients. The pathological findings in this series reflect the high risk of exposure to tuberculosis and hepatitis in the intravenous drug abusers in Harlem.

  15. Basics of kidney biopsy: A nephrologist's perspective.

    PubMed

    Agarwal, S K; Sethi, S; Dinda, A K

    2013-07-01

    The introduction of the kidney biopsy is one of the major events in the history of nephrology. Primary indications of kidney biopsy are glomerular hematuria/proteinuria with or without renal dysfunction and unexplained renal failure. Kidney biopsy is usually performed in prone position but in certain situations, supine and lateral positions may be required. Biopsy needles have changed with times from Vim-Silverman needle to Tru-cut needle to spring-loaded automatic gun. The procedure has also changed from blind bedside kidney biopsy to ultrasound marking to real-time ultrasound guidance to rarely computerized tomography guidance and laparoscopic and open biopsy. In very specific situations, transjugular kidney biopsy may be required. Most of the centers do kidney biopsy on short 1-day admission, whereas some take it as an outdoor procedure. For critical interpretation of kidney biopsy, adequate sample and clinical information are mandatory. Tissue needs to be stained with multiple stains for delineation of various components of kidney tissue. Many consider that electron microscopy (EM) is a must for all kidney biopsies, but facilities for EM are limited even in big centers. Sophisticated tests such as immunohistochemistry and in-situ hybridization are useful adjuncts for definitive diagnosis in certain situations.

  16. Kidney Biopsy: An Experience from Tertiary Hospital.

    PubMed

    Ghimire, Madhav; Pahari, Bishnu; Paudel, Navaraj; Das, Gayatri; Das, Gopal Chandra; Sharma, Sanjib Kumar

    2014-01-01

    Kidney Biopsy is an important diagnostic tool in Nephrology. It is useful in Nephrology in terms of diagnosis, prognosis and management. There is little information on renal biopsy data from central Nepal. We describe our center`s experience in kidney biopsy in term of histological patterns, complications and outcomes. We prospectively analyzed the biopsies data of patients over a period of one and half year. All kinds of kidney disease patients were included for kidney biopsy, irrespective of their clinical syndromes and underlying diagnosis. A total of 75 biopsies were analyzed. Majority of them were females; 42 (56%). Most of the biopsies; 63 (84%) were from younger subjects ≤ 45 years and majority of them fell in the age group 11-20 years. Most common clinical renal syndrome to undergo biopsy was Sub Nephrotic range Proteinuria in 40 (53.3%). Among comorbid conditions, 40 (53.3%) had Hypertension. The most common histological pattern seen was Mesangial proliferative Glomerulonephritis seen in 18 (24%). Among complications associated with the procedure, macroscopic hematuria was seen in 5 (6.7%) cases and clinically significant perinephric hematoma causing pain was seen in 4 (5.3%). There was no mortality associated with biopsy procedure. Sub Nephrotic range Proteinuria was the commonest clinical renal Syndrome observed. In terms of renal histology, Mesangial Proliferative Glomerulonephritis (MesPGN) was the commonest histological pattern observed. Kidney biopsy is a safe procedure without any significant adverse events.

  17. Basics of kidney biopsy: A nephrologist's perspective

    PubMed Central

    Agarwal, S. K.; Sethi, S.; Dinda, A. K.

    2013-01-01

    The introduction of the kidney biopsy is one of the major events in the history of nephrology. Primary indications of kidney biopsy are glomerular hematuria/proteinuria with or without renal dysfunction and unexplained renal failure. Kidney biopsy is usually performed in prone position but in certain situations, supine and lateral positions may be required. Biopsy needles have changed with times from Vim–Silverman needle to Tru-cut needle to spring-loaded automatic gun. The procedure has also changed from blind bedside kidney biopsy to ultrasound marking to real-time ultrasound guidance to rarely computerized tomography guidance and laparoscopic and open biopsy. In very specific situations, transjugular kidney biopsy may be required. Most of the centers do kidney biopsy on short 1-day admission, whereas some take it as an outdoor procedure. For critical interpretation of kidney biopsy, adequate sample and clinical information are mandatory. Tissue needs to be stained with multiple stains for delineation of various components of kidney tissue. Many consider that electron microscopy (EM) is a must for all kidney biopsies, but facilities for EM are limited even in big centers. Sophisticated tests such as immunohistochemistry and in-situ hybridization are useful adjuncts for definitive diagnosis in certain situations. PMID:23960337

  18. Hyperinsulinemic-euglycemic clamp in the conscious rat.

    PubMed

    Hughey, Curtis C; Hittel, Dustin S; Johnsen, Virginia L; Shearer, Jane

    2011-02-07

    Type 2 diabetes (T2D) is rapidly rising in prevalence. Characterized by either inadequate insulin production or the inability to utilize insulin produced, T2D results in elevated blood glucose levels. The "gold-standard" in assessing insulin sensitivity is a hyperinsulinemic-euglycemic clamp or insulin clamp. In this procedure, insulin is infused at a constant rate resulting in a drop in blood glucose. To maintain blood glucose at a constant level, exogenous glucose (D50) is infused into the venous circulation. The amount of glucose infused to maintain homeostasis is indicative of insulin sensitivity. Here, we show the basic clamp procedure in the chronically catheterized, unrestrained, conscious rat. This model allows blood to be collected with minimal stress to the animal. Following the induction of anesthesia, a midline incision is made and the left common carotid artery and right jugular vein are catheterized. Inserted catheters are flushed with heparinized saline, then exteriorized and secured. Animals are allowed to recover for 4-5 days prior to experiments, with weight gain monitored daily. Only those animals who regain weight to pre-surgery levels are used for experiments. On the day of the experiment, rats are fasted and connected to pumps containing insulin and D50. Baseline glucose is assessed from the arterial line and used a benchmark throughout the experiment (euglycemia). Following this, insulin is infused at a constant rate into the venous circulation. To match the drop in blood glucose, D50 is infused. If the rate of D50 infusion is greater than the rate of uptake, a rise in glucose will occur. Similarly, if the rate is insufficient to match whole body glucose uptake, a drop will occur. Titration of glucose continues until stable glucose readings are achieved. Glucose levels and glucose infusion rates during this stable period are recorded and reported. Results provide an index of whole body insulin sensitivity. The technique can be refined to meet

  19. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording

    PubMed Central

    Kolb, Ilya; Kodandaramaiah, Suhasa B.; Chubykin, Alexander A.; Yang, Aimei; Bear, Mark F.; Boyden, Edward S.; Forest, Craig R.

    2014-01-01

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation. PMID:25429119

  20. Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs.

    PubMed

    Bhatt, Sasmira; Alison, Beth J; Wallace, Euan M; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; te Pas, Arjan B; Morley, Colin J; Polglase, Graeme R; Hooper, Stuart B

    2013-04-15

    Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 ± 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by ∼30%) and CaBF (from 30.2 ± 5.6 to 40.1 ± 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by ∼40%) and right ventricular output (RVO; from 114.6 ± 14.4 to 38.8 ± 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 ± 3.8 to 119.2 ± 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.

  1. Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs

    PubMed Central

    Bhatt, Sasmira; Alison, Beth J; Wallace, Euan M; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; te Pas, Arjan B; Morley, Colin J; Polglase, Graeme R; Hooper, Stuart B

    2013-01-01

    Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 ± 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3–4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by ∼30%) and CaBF (from 30.2 ± 5.6 to 40.1 ± 4.6 ml min−1 kg−1), which then decreased again within 30–60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by ∼40%) and right ventricular output (RVO; from 114.6 ± 14.4 to 38.8 ± 9.7 ml min−1 kg−1), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 ± 3.8 to 119.2 ± 10.6 ml min−1 kg−1, did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3–4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period. PMID:23401615

  2. Consequences of pneumoperitoneum on liver ischemia during laparoscopic portal triad clamping in a swine model.

    PubMed

    Nsadi, Berthier; Gilson, Nathalie; Pire, Emilie; Cheramy, Jean-Paul; Pincemail, Joel; Scagnol, Irène; Meurisse, Michel; Defraigne, Jean-Olivier; Detry, Olivier

    2011-03-01

    Portal triad clamping (PTC) may be required during laparoscopic liver resection to limit blood loss. The aim of this study was to test in a swine model the hypothesis that during laparoscopic PTC, increased intraperitoneal pressure may alter hepatic vein reverse circulation, inducing a more severe hepatic ischemia compared with PTC performed in laparotomy. Fifteen pigs were randomized into three groups: laparoscopy (1 h of pneumoperitoneum at 15 mmHg and 3 h of surveillance), open PTC (1 h PTC through laparotomy and 3 h of reperfusion), and laparoscopic PTC (1 h PTC with 15 mmHg pneumoperitoneum and 3 h of reperfusion). PTC was performed under mesenteric decompression using a veno-venous splenofemoral bypass. Hepatic partial oxygen tension and microcirculatory flow were continuously measured using a Clarke-type electrode and a laser Doppler flow probe, respectively. Liver consequences of PTC was assessed by right atrium serum determination of transaminases, creatinine, bilirubin, INR, and several ischemia/reperfusion parameters, drawn before PTC (T0), before unclamping (T60), and 1 (T120) and 3 h after reperfusion (T240). Histology was performed on T240 liver biopsies. Compared with open PTC, laparoscopic PTC produced a more rapid and more severe decrease in hepatic oxygen tension, indicating a more severe tissular hypoxia, and a more severe decrease in hepatic microcirculatory flow, indicating a decrease in hepatic backflow. At T240, the laparoscopic PTC livers suffered from a higher degree of hepatocellular damage, shown by higher transaminases and increased necrotic index at pathology. These results indicate that in this pig model, laparoscopic PTC induces a more severe liver ischemia, related to decreased hepatic oxygen content and decreased hepatic backflow. If confirmed by clinical studies, these results may indicate that caution is necessary when performing prolonged PTC during laparoscopic hepatic resection, particularly in cirrhotic or steatotic livers

  3. Beliefs and practices of obstetric care providers regarding umbilical cord clamping.

    PubMed

    Hill, Allyson L; Fontenot, Holly B

    2014-01-01

    The optimal timing for umbilical cord clamping after birth has yet to be established, and controversy exists. There is evidence of potentially significant health benefits of delayed cord clamping for both full-term and preterm newborns, but this practice has not been widely adopted. This column takes a second look at two recent studies in which researchers examined the beliefs and practices of obstetric care providers regarding umbilical cord clamping in North America. Nurses who are aware of the latest science and who understand both existing practice patterns as well as practice barriers to delayed clamping can be leaders in and advocates for change. © 2014 AWHONN.

  4. Modeling considerations for the analysis of LMFBR steam generator tube clamps

    SciTech Connect

    Lay, D.M.; Piper, R.M.

    1982-01-01

    In the design of the Babcock and Wilcox Helical Coil Liquid Metal Fast Breeder Reactor (LMFBR) Steam Generator, the tube bundle is connected to the feedwater and steam plenums via ''inlet/outlet tubes''. Of prime importance in the design of these tubes is the tube-to-tube and tube-to-shell clamps which are provided to prevent detrimental vibration. This paper presents a method of modeling the tube-to-tube clamps to accurately predict tube-to-clamp interaction in the finite element analysis. It also demonstrates the validity of specific modeling assumptions in determining stresses in the clamp assembly.

  5. Mechanism of ATP-driven PCNA clamp loading by S. cerevisiae RFC.

    PubMed

    Chen, Siying; Levin, Mikhail K; Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2009-05-08

    Circular clamps tether polymerases to DNA, serving as essential processivity factors in genome replication, and function in other critical cellular processes as well. Clamp loaders catalyze clamp assembly onto DNA, and the question of how these proteins construct a topological link between a clamp and DNA, especially the mechanism by which ATP is utilized for the task, remains open. Here we describe pre-steady-state analysis of ATP hydrolysis, proliferating cell nuclear antigen (PCNA) clamp opening, and DNA binding by Saccharomyces cerevisiae replication factor C (RFC), and present the first kinetic model of a eukaryotic clamp-loading reaction validated by global data analysis. ATP binding to multiple RFC subunits initiates a slow conformational change in the clamp loader, enabling it to bind and open PCNA and to bind DNA as well. PCNA opening locks RFC into an active state, and the resulting RFC.ATP.PCNA((open)) intermediate is ready for the entry of DNA into the clamp. DNA binding commits RFC to ATP hydrolysis, which is followed by PCNA closure and PCNA.DNA release. This model enables quantitative understanding of the multistep mechanism of a eukaryotic clamp loader and furthermore facilitates comparative analysis of loaders from diverse organisms.

  6. Self-clamping arc light reflector for welding torch

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S. (Inventor)

    1987-01-01

    This invention is directed to a coaxial extending metal mirror reflector attached to the electrode housing or gas cup on a welding torch. An electric welding torch with an internal viewing system for robotic welding is provded with an annular arc light reflector to reflect light from the arc back onto the workpiece. The reflector has a vertical split or gap in its surrounding wall to permit the adjacent wall ends forming the split to be sprung open slightly to permit the reflector to be removed or slipped onto the torch housing or gas cup. The upper opening of the reflector is slightly smaller than the torch housing or gas cup and therefore, when placed on the torch housing or gas cup has that springiness to cause it to clamp tightly on the housing or gas cup. The split or gap also serves to permit the feed of weld wire through to the weld area,

  7. Self-clamping arc light reflector for welding torch

    NASA Astrophysics Data System (ADS)

    Gordon, Stephen S.

    1987-07-01

    This invention is directed to a coaxial extending metal mirror reflector attached to the electrode housing or gas cup on a welding torch. An electric welding torch with an internal viewing system for robotic welding is provded with an annular arc light reflector to reflect light from the arc back onto the workpiece. The reflector has a vertical split or gap in its surrounding wall to permit the adjacent wall ends forming the split to be sprung open slightly to permit the reflector to be removed or slipped onto the torch housing or gas cup. The upper opening of the reflector is slightly smaller than the torch housing or gas cup and therefore, when placed on the torch housing or gas cup has that springiness to cause it to clamp tightly on the housing or gas cup. The split or gap also serves to permit the feed of weld wire through to the weld area,

  8. Non-Linear Vibration Characteristics of Clamped Laminated Shallow Shells

    NASA Astrophysics Data System (ADS)

    ABE, A.; KOBAYASHI, Y.; YAMADA, G.

    2000-07-01

    This paper examines non-linear free vibration characteristics of first and second vibration modes of laminated shallow shells with rigidly clamped edges. Non-linear equations of motion for the shells based on the first order shear deformation and classical shell theories are derived by means of Hamilton's principle. We apply Galerkin's procedure to the equations of motion in which eigenvectors for first and second modes of linear vibration obtained by the Ritz method are employed as trial functions. Then simultaneous non-linear ordinary differential equations are derived in terms of amplitudes of the first and second vibration modes. Backbone curves for the first and second vibration modes are solved numerically by the Gauss-Legendre integration method and the shooting method respectively. The effects of lamination sequences and transverse shear deformation on the behavior are discussed. It is also shown that the motion of the first vibration mode affects the response for the second vibration mode.

  9. Priming and testing silicon patch-clamp neurochips.

    PubMed

    Py, Christophe; Denhoff, Michael W; Sabourin, Nicaulas; Weber, John; Shiu, Matthew; Zhao, Ping

    2014-09-25

    We report on the systematic and automated priming and testing of silicon planar patch-clamp chips after their assembly in Plexiglas packages and sterilization in an air plasma reactor. We find that almost 90% of the chips are successfully primed by our automated setup, and have a shunt capacitance of between 10 pF and 30 pF. Blocked chips are mostly due to glue invasion in the well, and variability in the manual assembly process is responsible for the distribution in shunt capacitance value. Priming and testing time with our automated setup is less than 5 min per chip, which is compatible with the production of large series for use in electrophysiology experiments.

  10. The timing of umbilical cord clamping at birth: physiological considerations.

    PubMed

    Hooper, Stuart B; Binder-Heschl, Corinna; Polglase, Graeme R; Gill, Andrew W; Kluckow, Martin; Wallace, Euan M; Blank, Douglas; Te Pas, Arjan B

    2016-01-01

    While it is now recognized that umbilical cord clamping (UCC) at birth is not necessarily an innocuous act, there is still much confusion concerning the potential benefits and harms of this common procedure. It is most commonly assumed that delaying UCC will automatically result in a time-dependent net placental-to-infant blood transfusion, irrespective of the infant's physiological state. Whether or not this occurs, will likely depend on the infant's physiological state and not on the amount of time that has elapsed between birth and umbilical cord clamping (UCC). However, we believe that this is an overly simplistic view of what can occur during delayed UCC and ignores the benefits associated with maintaining the infant's venous return and cardiac output during transition. Recent experimental evidence and observations in humans have provided compelling evidence to demonstrate that time is not a major factor influencing placental-to-infant blood transfusion after birth. Indeed, there are many factors that influence blood flow in the umbilical vessels after birth, which depending on the dominating factors could potentially result in infant-to-placental blood transfusion. The most dominant factors that influence umbilical artery and venous blood flows after birth are lung aeration, spontaneous inspirations, crying and uterine contractions. It is still not entirely clear whether gravity differentially alters umbilical artery and venous flows, although the available data suggests that its influence, if present, is minimal. While there is much support for delaying UCC at birth, much of the debate has focused on a time-based approach, which we believe is misguided. While a time-based approach is much easier and convenient for the caregiver, ignoring the infant's physiology during delayed UCC can potentially be counter-productive for the infant.

  11. The human dynamic clamp as a paradigm for social interaction

    PubMed Central

    Dumas, Guillaume; de Guzman, Gonzalo C.; Tognoli, Emmanuelle; Kelso, J. A. Scott

    2014-01-01

    Social neuroscience has called for new experimental paradigms aimed toward real-time interactions. A distinctive feature of interactions is mutual information exchange: One member of a pair changes in response to the other while simultaneously producing actions that alter the other. Combining mathematical and neurophysiological methods, we introduce a paradigm called the human dynamic clamp (HDC), to directly manipulate the interaction or coupling between a human and a surrogate constructed to behave like a human. Inspired by the dynamic clamp used so productively in cellular neuroscience, the HDC allows a person to interact in real time with a virtual partner itself driven by well-established models of coordination dynamics. People coordinate hand movements with the visually observed movements of a virtual hand, the parameters of which depend on input from the subject’s own movements. We demonstrate that HDC can be extended to cover a broad repertoire of human behavior, including rhythmic and discrete movements, adaptation to changes of pacing, and behavioral skill learning as specified by a virtual “teacher.” We propose HDC as a general paradigm, best implemented when empirically verified theoretical or mathematical models have been developed in a particular scientific field. The HDC paradigm is powerful because it provides an opportunity to explore parameter ranges and perturbations that are not easily accessible in ordinary human interactions. The HDC not only enables to test the veracity of theoretical models, it also illuminates features that are not always apparent in real-time human social interactions and the brain correlates thereof. PMID:25114256

  12. Calcium entry in squid axons during voltage clamp pulses.

    PubMed

    Requena, J; Whittembury, J; Mullins, L J

    1989-01-01

    Squid giant axons were injected with aequorin and tetraethylammonium and were impaled with sodium ion sensitive, current and voltage electrodes. The axons were usually bathed in a solution of varying Ca2+ concentration ([Ca2+]o) containing 150mM each of Na+, K+ and an inert cation such as Li+, Tris or N-methylglucamine and had ionic currents pharmacologically blocked. Voltage clamp pulses were repeatedly delivered to the extent necessary to induce a change in the aequorin light emission, a measure of axoplasmic Ca2+ level, [Ca2+]i. The effect of membrane voltage on [Ca2+]i was found to depend on the concentration of internal Na+ ([Na+]i). Voltage clamp hyperpolarizing pulses were found to cause a reduction of [Ca2+]i. For depolarizing pulses a relationship between [Ca2+]i gain and [Na+]i indicates that Ca2+ entry is sigmoid with a half maximal response at 22 mM Na+. This Ca2+ entry is a steep function of [Na+]i suggesting that 4 Na+ ions are required to promote the influx of 1 Ca2+. There was little change in Ca2+ entry with depolarizing pulses when [Ca2+]o is varied from 1 to 10mM, while at 50mM [Ca2+]o calcium entry clearly increases suggesting an alternate pathway from that of Na+/Ca2+ exchange. This entry of Ca2+ at high [Ca2+]o, however, was not blocked by Cs+o. The results obtained lend further support to the notion that Na+/Ca2+ exchange in squid giant axon is sensitive to membrane voltage no matter whether this is applied as a constant change in membrane potential or as an intermittent one.

  13. Image-Guided Adrenal and Renal Biopsy

    PubMed Central

    Sharma, Karun V.; Venkatesan, Aradhana M.; Swerdlow, Daniel; DaSilva, Daniel; Beck, Avi; Jain, Nidhi; Wood, Bradford J.

    2010-01-01

    Image-guided biopsy is a safe and well-established technique that is familiar to most interventional radiologists (IRs). Improvements in image-guidance, biopsy tools and biopsy techniques now routinely allow for safe biopsy of renal and adrenal lesions which traditionally were considered difficult to reach or technically challenging. Image-guided biopsy is used to establish the definitive tissue diagnosis in adrenal mass lesions that can not be fully characterized with imaging or laboratory tests alone. It is also used to establish definitive diagnosis in some cases of renal parenchymal disease and has an expanding role in diagnosis and characterization of renal masses prior to treatment. Although basic principles and techniques for image-guided needle biopsy are similar regardless of organ, this paper will highlight some technical considerations, indications and complications which are unique to the adrenal gland and kidney because of their anatomic location and physiologic features. PMID:20540919

  14. Evaluation of GSTP1 and APC methylation as indicators for repeat biopsy in a high-risk cohort of men with negative initial prostate biopsies

    PubMed Central

    Trock, Bruce J.; Brotzman, Michelle J.; Mangold, Leslie A.; Bigley, Joseph W.; Epstein, Jonathan I.; McLeod, David; Klein, Eric A.; Jones, J. Stephen; Wang, Songbai; McAskill, Theresa; Mehrotra, Jyoti; Raghavan, Bhargavi; Partin, Alan W.

    2011-01-01

    OBJECTIVE To evaluate the performance of DNA methylation biomarkers in the setting of repeat biopsy in men with an initially negative prostate biopsy but a high index of suspicion for missed prostate cancer. PATIENTS AND METHODS We prospectively evaluated 86 men with an initial histologically negative prostate biopsy and high-risk features. All men underwent repeat 12-core ultrasonography-guided biopsy. DNA methylation of glutathione-S-transferase P1 (GSTP1) and adenomatous polyposis coli (APC) was determined using tissue from the initially negative biopsy and compared with histology of the repeat biopsy. The primary outcome was the relative negative predictive value (NPV) of APC compared with GSTP1, and its 95% confidence interval (CI). RESULTS On repeat biopsy, 21/86 (24%) men had prostate cancer. APC and GSTP1 methylation ratios below the threshold (predicting no cancer) produced a NPV of 0.96 and 0.80, respectively. The relative NPV was 1.2 (95% CI: 1.06–1.36), indicating APC has significantly higher NPV. Methylation ratios above the threshold yielded a sensitivity of 0.95 for APC and 0.43 for GSTP1. Combining both methylation markers produced a performance similar to that of APC alone. APC methylation patterns were consistent with a possible field effect or occurrence early in carcinogenesis. CONCLUSION APC methylation provided a very high NPV with a low percentage of false-negatives, in the first prospective study to evaluate performance of DNA methylation markers in a clinical cohort of men undergoing repeat biopsy. The potential of APC methylation to reduce unnecessary repeat biopsies warrants validation in a larger prospective cohort. PMID:22077694

  15. Biopsy-proven childhood glomerulonephritis in Johor.

    PubMed

    Khoo, J J; Pee, S; Thevarajah, B; Yap, Y C; Chin, C K

    2004-06-01

    There has been no published study of biopsy-proven childhood glomerulonephritis in Malaysia. To determine the pattern of childhood glomerulonephritis in Johor, Malaysia from a histopathological perspective and the various indications used for renal biopsy in children. Retrospective study was done of all renal biopsies from children under 16 years of age, received in Sultanah Aminah Hospital, Johor between 1994 and 2001. The histopathological findings were reviewed to determine the pattern of biopsy-proven glomerulonephritis. The indications for biopsy, mode of therapy given after biopsy and the clinical outcome were studied. 122 adequate biopsies were received, 9 children had repeat biopsies. Of the 113 biopsies, minimal change disease formed the most common histopathological diagnosis (40.7%) while lupus nephritis formed the most common secondary glomerulonephritis (23.0%). The main indications for biopsy were nephrotic syndrome (50.8%), lupus nephritis (25.4%) and renal impairment (13.1%). The mode of therapy was changed in 59.8% of the children. Of 106 patients followed-up, 84 children were found to have normal renal function in remission or on treatment. 4 patients developed chronic renal impairment and 16 reached end stage renal disease. Five of the 16 children with end stage disease had since died while 11 were on renal replacement therapy. Another 2 patients died of other complications. The pattern of childhood GN in our study tended to reflect the more severe renal parenchymal diseases in children and those requiring more aggressive treatment. This was because of our criteria of selection (indication) for renal biopsy. Renal biopsy where performed appropriately in selected children may not only be a useful investigative tool for histological diagnosis and prognosis but may help clinicians plan the optimal therapy for these children.

  16. Conjunctival biopsy in infantile neuroaxonal dystrophy.

    PubMed

    Ferreira, R C; Mierau, G W; Bateman, J B

    1997-02-01

    To describe a case of infantile neuroaxonal dystrophy with optic nerve atrophy and to discuss the diagnostic role of conjunctival biopsy. We performed a complete ophthalmologic examination and a diagnostic conjunctival biopsy on a girl with a neurodegenerative disease. On the basis of "spheroid" inclusions in the unmyelinated axons, we diagnosed infantile neuoroaxonal dystrophy. Optic atrophy is an important finding in infantile neuroaxonal dystrophy, and conjunctival biopsy is a reliable and very convenient diagnostic test.

  17. Percutaneous computed tomography-guided aspiration and biopsy of intrathoracic lesions: Results of 265 procedures

    PubMed Central

    Neyaz, Zafar; Lal, Hira; Thakral, Anuj; Nath, Alok; Rao, Ram Naval; Verma, Ritu

    2016-01-01

    Context: Percutaneous computed tomography (CT)-guided needle aspiration and biopsy technique have developed over time as a method for obtaining tissue specimen. Although this is a minimally invasive procedure, complications do occasionally occur. Aims: The aim of the study was to evaluate the diagnostic yield and complications of 265 percutaneous CT-guided aspiration and biopsy procedures performed on various intrathoracic lesions. Settings and Design: Data of percutaneous CT-guided aspiration and biopsy procedures of intrathoracic lesions performed over a 4 year period were retrospectively analyzed. Subjects and Methods: Procedure details, radiological images, and pathological and microbiological reports were retrieved from radiology records and hospital information system. Technical success, diagnostic yield, and complication rates were calculated. Results: Total 265 procedures were performed for lung (n = 179), mediastinum (n = 73), and pleural lesions (n = 13). Diagnostic yield for lung, mediastinal, and pleural lesions was 80.7%, 74.2, and 75%, respectively, for core biopsy specimens. Major complication was noted in only one procedure (0.4%). Minor complications were noted in 13.6% procedures which could be managed conservatively. Conclusions: Percutaneous CT-guided aspiration and biopsy procedures for intrathoracic lesions are reasonably safe with good diagnostic yield. Complications are infrequent and conservatively managed in most of the cases. PMID:27890990

  18. Photoacoustic biopsy: a feasibility study

    NASA Astrophysics Data System (ADS)

    Xu, Guan; Tomlins, Scott A.; Siddiqui, Javed; Davis, Mandy A.; Kunju, Lakshmi P.; Wei, John T.; Wang, Xueding

    2015-03-01

    Photoacoustic (PA) measurements encode the information associated with both physical microstructures and chemical contents in biological tissues. A two-dimensional physio-chemical spectrogram (PCS) can be formulated by combining the power spectra of PA signals acquired at a series of optical wavelengths. The analysis of PCS, or namely PA physio-chemical analysis (PAPCA), enables the quantification of the concentrations and the spatial distributions of a variety of chemical components in the tissue. The chemical components and their distribution are the two major features observed in the biopsy procedures which have been regarded as the gold standard of the diagnosis of many diseases. Taking non-alcoholic fatty liver disease and prostate cancer for example, this study investigates the feasibility of PAPCA in characterizing the histopathological changes in the diseased conditions in biological tissue. A catheter based setup facilitating measurement in deep tissues was also proposed and tested.

  19. Analysis of impactor residues in tray clamps from the Long Duration Exposure Facility. Part 1: Clamps from Bay A of the satellite

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Bernhard, Ronald P.

    1993-01-01

    The Long Duration Exposure Facility (LDEF) was placed in low Earth orbit (LEO) in 1984 and was recovered 5.7 years later. The LDEF was host to several individual experiments that were specifically designed to characterize critical aspects of meteoroid and debris environment in LEO. It was realized from the beginning, however, that the most efficient use of the satellite would be to examine the entire surface of the Earth for impact features. In this regard, particular interest has centered on common exposed materials that faced in all LDEF pointing directions. Among the most important of these materials is the tray clamps. Therefore, in an effort to understand the nature of particulates in LEO and their effects on spacecraft hardware better, we are analyzing residues found in impact features on LDEF tray clamp surfaces. This catalog presents all data from clamps from Bay A of the LDEF. Subsequent catalogs will include clamps from succeeding bays of the satellite.

  20. Analysis of impactor residues in tray clamps from the Long Duration Exposure Facility. Part 1: Clamps from Bay A of the satellite

    SciTech Connect

    Zolensky, M.E.; Bernhard, R.P.

    1993-03-01

    The Long Duration Exposure Facility (LDEF) was placed in low Earth orbit (LEO) in 1984 and was recovered 5.7 years later. The LDEF was host to several individual experiments that were specifically designed to characterize critical aspects of meteoroid and debris environment in LEO. It was realized from the beginning, however, that the most efficient use of the satellite would be to examine the entire surface of the Earth for impact features. In this regard, particular interest has centered on common exposed materials that faced in all LDEF pointing directions. Among the most important of these materials is the tray clamps. Therefore, in an effort to understand the nature of particulates in LEO and their effects on spacecraft hardware better, residues found in impact features on LDEF tray clamp surfaces are being analyzed. This catalog presents all data from clamps from Bay A of the LDEF. Subsequent catalogs will include clamps from succeeding bays of the satellite.

  1. Prostate Biopsy: Current Status and Limitations

    PubMed Central

    Presti, Joseph C

    2007-01-01

    The technique of prostate biopsy has evolved over the past 10 years to improve our ability to detect prostate cancer. Extended biopsy schemes can be performed in the office under local anesthesia and are well tolerated. In addition to detection, the role of extended biopsy schemes in refining tumor grading and risk assessment has become better defined. This review discusses the evolution of prostate biopsy techniques from the sextant scheme to the extended scheme and demonstrates the latter’s utility in clinical decision making. PMID:17934565

  2. The timing of cord clamping and oxidative stress in term newborns.

    PubMed

    Díaz-Castro, Javier; Florido, Jesus; Kajarabille, Naroa; Garrido-Sánchez, Maria; Padilla, Carmen; de Paco, Catalina; Navarrete, Luis; Ochoa, Julio J

    2014-08-01

    Clamping and cutting of the umbilical cord is the most prevalent of all operations, but the optimal timing of cord clamping is controversial, with different timings offering advantages and disadvantages. This study, for the first time, compares the influence of early and late cord clamping in correlation with oxidative stress and inflammation signaling, Because cord clamping timing may have a significant influence on placenta-to-infant blood transfer, thereby modifying oxygenation of maternal and fetal tissues, and on the transfer of inflammatory mediators throughout the placenta. Sixty-four pregnant subjects were selected at the Gynecology and Obstetrics Services Department of the Clinico San Cecilio Hospital, Granada, Spain, based on disease-free women who experienced a normal course of pregnancy and a spontaneous, vaginal, single delivery. Half of the subjects had deliveries with early-clamped newborn infants (at 10 s), and the other half had late-clamped deliveries (at 2 min). Erythrocyte catalase activity was significantly greater in the late-clamped group than in the early-clamped group (P < .01 for the umbilical vein and P < .001 for the artery). The values for superoxide dismutase, total antioxidant status, and soluble tumor necrosis factor receptor II were all significantly higher in the late-clamped group compared with the early-clamped group (P < .01, P < .001, and P < .001, respectively). The results suggest a beneficial effect of late cord clamping, produced by an increase in antioxidant capacity and moderation of the inflammatory-mediated effects induced during delivery of term neonates. Copyright © 2014 by the American Academy of Pediatrics.

  3. Current umbilical cord clamping practices and attitudes of obstetricians and midwives toward delayed cord clamping in Saudi Arabia.

    PubMed

    Ibrahim, Nadia O; Sukkarieh, Hatouf H; Bustami, Rami T; Alshammari, Elaf A; Alasmari, Lama Y; Al-Kadri, Hanan M

    2017-01-01

    In Saudi Arabia, as in many countries, there is usually no clear definition of the timing of umbilical cord clamping (UCC) in the policies and procedures used by hospitals. The World Health Organization (WHO) recommends delayed cord clamping (DCC) ( > 1 minute after birth) as it can significantly improve hemodynamics and long-term neurodevelopment. To investigate current practices of healthcare professionals on the timing of UCC in Saudi Arabia. Cross-sectional survey. Five tertiary hospitals in Riyadh, Saudi Arabia, during May to October 2016. Obstetricians and midwives completed a widely-used questionnaire on UCC practices. Current UCC practices and attitudes of obstetricians and midwives toward DCC. Eighty-two obstetricians and 75 midwives completed the questionnaire for a response rate of 80%. The majority of respondents were aged 30 years or older (81%) and 84% were females. Most respondents were non-Saudi (66%) and had an educational level of bachelor's degree or higher (72%). Only 42% of respondents reported the existence of UCC guidelines in their practice; 38% reported the existence of a set time for UCC when the neonate was term and healthy, and only 32% had a set time for UCC in preterm neonates. While lower levels of agreement were reported among obstetricians and midwives on the benefits of DCC for babies requiring positive pressure ventilation, the majority of respondents (69-71%) thought that DCC was generally good for both term and preterm babies and that its benefits extend beyond the neonatal period. While the majority of obstetricians and midwives that participated in this study had a positive perception toward DCC, this did not translate to their daily practice as most of these professionals reported a lack of existing UCC guidelines in their institutions. Further studies are warranted to confirm these findings. Participant selection by convenience sampling.

  4. Fluoroscopy-Guided Percutaneous Vertebral Body Biopsy Using a Novel Drill-Powered Device: Technical Case Series.

    PubMed

    Wallace, Adam N; Pacheco, Rafael A; Tomasian, Anderanik; Hsi, Andy C; Long, Jeremiah; Chang, Randy O; Jennings, Jack W

    2016-02-01

    A novel coaxial biopsy system powered by a handheld drill has recently been introduced for percutaneous bone biopsy. This technical note describes our initial experience performing fluoroscopy-guided vertebral body biopsies with this system, compares the yield of drill-assisted biopsy specimens with those obtained using a manual technique, and assesses the histologic adequacy of specimens obtained with drill assistance. Medical records of all single-level, fluoroscopy-guided vertebral body biopsies were reviewed. Procedural complications were documented according to the Society of Interventional Radiology classification. The total length of bone core obtained from drill-assisted biopsies was compared with that of matched manual biopsies. Pathology reports were reviewed to determine the histologic adequacy of specimens obtained with drill assistance. Twenty eight drill-assisted percutaneous vertebral body biopsies met study inclusion criteria. No acute complications were reported. Of the 86 % (24/28) of patients with clinical follow-up, no delayed complications were reported (median follow-up, 28 weeks; range 5-115 weeks). The median total length of bone core obtained from drill-assisted biopsies was 28 mm (range 8-120 mm). This was longer than that obtained from manual biopsies (median, 20 mm; range 5-45 mm; P = 0.03). Crush artifact was present in 11 % (3/28) of drill-assisted biopsy specimens, which in one case (3.6 %; 1/28) precluded definitive diagnosis. A drill-assisted, coaxial biopsy system can be used to safely obtain vertebral body core specimens under fluoroscopic guidance. The higher bone core yield obtained with drill assistance may be offset by the presence of crush artifact.

  5. Fluoroscopy-Guided Percutaneous Vertebral Body Biopsy Using a Novel Drill-Powered Device: Technical Case Series

    SciTech Connect

    Wallace, Adam N. Pacheco, Rafael A. Tomasian, Anderanik; Hsi, Andy C.; Long, Jeremiah; Chang, Randy O.; Jennings, Jack W.

    2016-02-15

    BackgroundA novel coaxial biopsy system powered by a handheld drill has recently been introduced for percutaneous bone biopsy. This technical note describes our initial experience performing fluoroscopy-guided vertebral body biopsies with this system, compares the yield of drill-assisted biopsy specimens with those obtained using a manual technique, and assesses the histologic adequacy of specimens obtained with drill assistance.MethodsMedical records of all single-level, fluoroscopy-guided vertebral body biopsies were reviewed. Procedural complications were documented according to the Society of Interventional Radiology classification. The total length of bone core obtained from drill-assisted biopsies was compared with that of matched manual biopsies. Pathology reports were reviewed to determine the histologic adequacy of specimens obtained with drill assistance.ResultsTwenty eight drill-assisted percutaneous vertebral body biopsies met study inclusion criteria. No acute complications were reported. Of the 86 % (24/28) of patients with clinical follow-up, no delayed complications were reported (median follow-up, 28 weeks; range 5–115 weeks). The median total length of bone core obtained from drill-assisted biopsies was 28 mm (range 8–120 mm). This was longer than that obtained from manual biopsies (median, 20 mm; range 5–45 mm; P = 0.03). Crush artifact was present in 11 % (3/28) of drill-assisted biopsy specimens, which in one case (3.6 %; 1/28) precluded definitive diagnosis.ConclusionsA drill-assisted, coaxial biopsy system can be used to safely obtain vertebral body core specimens under fluoroscopic guidance. The higher bone core yield obtained with drill assistance may be offset by the presence of crush artifact.

  6. Renal mass biopsy--a renaissance?

    PubMed

    Lane, Brian R; Samplaski, Mary K; Herts, Brian R; Zhou, Ming; Novick, Andrew C; Campbell, Steven C

    2008-01-01

    Advances in our understanding of the natural history and limited aggressive potential of many small renal masses, expanding treatment options and the integration of molecular factors into prognostic and therapeutic algorithms have stimulated renewed interest in percutaneous renal mass biopsy. A comprehensive literature review was performed using MEDLINE/PubMed to evaluate the indications, techniques, complications and efficacy of renal mass biopsy. Reported techniques of renal mass biopsy vary widely with different modes of radiographic guidance, needle size, number of cores and pathological analyses. Percutaneous renal mass biopsy with 2 or 3 cores using 18 gauge needles may improve diagnostic accuracy without increasing morbidity. Serious complications of percutaneous biopsy are rare and the minor complication rate in recent series has been less than 5%. The reported rate of technical failure of renal mass biopsy due to insufficient material was about 9% before 2001 and 5% in more recent studies. The likelihood of indeterminate or inaccurate pathological findings has decreased from 10% to 4% when comparing clinical studies before and since 2001. Currently a total success rate of greater than 90% is attainable using renal mass biopsy with standard histopathological analysis. Recent studies demonstrated that combining immunohistochemical and molecular analyses may further improve renal mass biopsy accuracy. Research on expanded analysis of percutaneous renal mass biopsy specimens should remain a top priority. Enhanced renal mass biopsy should not change treatment in most patients with small renal masses, who should be treated with surgical excision. However, future clinical algorithms will likely incorporate enhanced biopsy in situations in which decision making is more challenging.

  7. Regulation of Interactions with Sliding Clamps During DNA Replication and Repair

    PubMed Central

    López de Saro, Francisco J.

    2009-01-01

    The molecular machines that replicate the genome consist of many interacting components. Essential to the organization of the replication machinery are ring-shaped proteins, like PCNA (Proliferating Cell Nuclear Antigen) or the β- clamp, collectively named sliding clamps. They encircle the DNA molecule and slide on it freely and bidirectionally. Sliding clamps are typically associated to DNA polymerases and provide these enzymes with the processivity required to synthesize large chromosomes. Additionally, they interact with a large array of proteins that perform enzymatic reactions on DNA, targeting and orchestrating their functions. In recent years there have been a large number of studies that have analyzed the structural details of how sliding clamps interact with their ligands. However, much remains to be learned in relation to how these interactions are regulated to occur coordinately and sequentially. Since sliding clamps participate in reactions in which many different enzymes bind and then release from the clamp in an orchestrated way, it is critical to analyze how these changes in affinity take place. In this review I focus the attention on the mechanisms by which various types of enzymes interact with sliding clamps and what is known about the regulation of this binding. Especially I describe emerging paradigms on how enzymes switch places on sliding clamps during DNA replication and repair of prokaryotic and eukaryotic genomes. PMID:19881914

  8. Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes

    NASA Astrophysics Data System (ADS)

    Gómez-González, J. F.; Destexhe, A.; Bal, T.

    2014-10-01

    Objective. Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. Approach. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). Main results. We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. Significance. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

  9. A Comparison of the Performance and Application Differences Between Manual and Automated Patch-Clamp Techniques

    PubMed Central

    Yajuan, Xiao; Xin, Liang; Zhiyuan, Li

    2012-01-01

    The patch clamp technique is commonly used in electrophysiological experiments and offers direct insight into ion channel properties through the characterization of ion channel activity. This technique can be used to elucidate the interaction between a drug and a specific ion channel at different conformational states to understand the ion channel modulators’ mechanisms. The patch clamp technique is regarded as a gold standard for ion channel research; however, it suffers from low throughput and high personnel costs. In the last decade, the development of several automated electrophysiology platforms has greatly increased the screen throughput of whole cell electrophysiological recordings. New advancements in the automated patch clamp systems have aimed to provide high data quality, high content, and high throughput. However, due to the limitations noted above, automated patch clamp systems are not capable of replacing manual patch clamp systems in ion channel research. While automated patch clamp systems are useful for screening large amounts of compounds in cell lines that stably express high levels of ion channels, the manual patch clamp technique is still necessary for studying ion channel properties in some research areas and for specific cell types, including primary cells that have mixed cell types and differentiated cells that derive from induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs). Therefore, further improvements in flexibility with regard to cell types and data quality will broaden the applications of the automated patch clamp systems in both academia and industry. PMID:23346269

  10. Structural insight into β-Clamp and its interaction with DNA Ligase in Helicobacter pylori.

    PubMed

    Pandey, Preeti; Tarique, Khaja Faisal; Mazumder, Mohit; Rehman, Syed Arif Abdul; Kumari, Nilima; Gourinath, Samudrala

    2016-08-08

    Helicobacter pylori, a gram-negative and microaerophilic bacterium, is the major cause of chronic gastritis, gastric ulcers and gastric cancer. Owing to its central role, DNA replication machinery has emerged as a prime target for the development of antimicrobial drugs. Here, we report 2Å structure of β-clamp from H. pylori (Hpβ-clamp), which is one of the critical components of DNA polymerase III. Despite of similarity in the overall fold of eubacterial β-clamp structures, some distinct features in DNA interacting loops exists that have not been reported previously. The in silico prediction identified the potential binders of β-clamp such as alpha subunit of DNA pol III and DNA ligase with identification of β-clamp binding regions in them and validated by SPR studies. Hpβ-clamp interacts with DNA ligase in micromolar binding affinity. Moreover, we have successfully determined the co-crystal structure of β-clamp with peptide from DNA ligase (not reported earlier in prokaryotes) revealing the region from ligase that interacts with β-clamp.

  11. Structural insight into β-Clamp and its interaction with DNA Ligase in Helicobacter pylori

    PubMed Central

    Pandey, Preeti; Tarique, Khaja Faisal; Mazumder, Mohit; Rehman, Syed Arif Abdul; kumari, Nilima; Gourinath, Samudrala

    2016-01-01

    Helicobacter pylori, a gram-negative and microaerophilic bacterium, is the major cause of chronic gastritis, gastric ulcers and gastric cancer. Owing to its central role, DNA replication machinery has emerged as a prime target for the development of antimicrobial drugs. Here, we report 2Å structure of β-clamp from H. pylori (Hpβ-clamp), which is one of the critical components of DNA polymerase III. Despite of similarity in the overall fold of eubacterial β-clamp structures, some distinct features in DNA interacting loops exists that have not been reported previously. The in silico prediction identified the potential binders of β-clamp such as alpha subunit of DNA pol III and DNA ligase with identification of β-clamp binding regions in them and validated by SPR studies. Hpβ-clamp interacts with DNA ligase in micromolar binding affinity. Moreover, we have successfully determined the co-crystal structure of β-clamp with peptide from DNA ligase (not reported earlier in prokaryotes) revealing the region from ligase that interacts with β-clamp. PMID:27499105

  12. Transperineal prostate biopsy detects significant cancer in patients with elevated prostate-specific antigen (PSA) levels and previous negative transrectal biopsies.

    PubMed

    Dimmen, Magne; Vlatkovic, Ljiljana; Hole, Knut-Håkon; Nesland, Jahn M; Brennhovd, Bjørn; Axcrona, Karol

    2012-07-01

    Several authors have previously reported that transrectal prostate biopsy has a false-negative rate of 20-30%, and that a number of prostate cancers missed on transrectal biopsy can be detected by transperineal biopsy. It has also been shown that most of these tumours are located anteriorly in the prostate gland. The present study showed a high rate of prostate cancer in patients with previous negative transrectal biopsies but elevated PSA levels, and that the cancers were located anteriorly in the prostate gland. Also, most of these cancers were clinically significant in patients that underwent RP, i.e. a high proportion of cancers were high-grade/high-stage tumours. We also showed that the transperineal biopsy technique can be applied successfully to patients with a closed anal orifice after previous surgery for rectal cancer. Transperineal biopsy can be done safely without routine antibiotic prophylaxis. To investigate the outcomes of transperineal prostate biopsies in patients with elevated prostate-specific antigen (PSA) levels and negative transrectal biopsies. The aim of this retrospective study was to evaluate the diagnostic yield of the transperineal biopsy approach in these patients, and to evaluate the pathology findings in subsequent radical prostatectomy (RP) specimens in patients undergoing RP. In all, 69 consecutive patients with previous negative transrectal biopsies but elevated PSA levels investigated at urological units in Norway who had been referred to The Norwegian Radium Hospital were included. The patients had undergone a mean (median; range) of 2.42 (2; 0-7) transrectal biopsies. The mean (range) age was 63.1 (42-78) years. The median (range) PSA level was 12 (4.3-229) ng/mL. The patients were examined with transperineal biopsy of the prostate between July 2007 and February 2009. The results of the transperineal biopsies were reviewed for Gleason biopsy score, and these were compared with the histopathology results of the RP specimens, i

  13. Evaluation of methods for the isolation of high quality RNA from bovine and cervine hide biopsies.

    PubMed

    Brannan, Jaime L; Holman, Patricia J; Olafson, Pia U; Pruett, John H; Riggs, Penny K

    2013-02-01

    Molecular investigations of the ruminant response to ectoparasites at the parasite-host interface are critically dependent upon the quality of RNA. The complexity of ruminant skin decreases the capacity to obtain high quality RNA from biopsy samples, which directly affects the reliability of data produced by gene expression experiments. Two methods for isolating total RNA from skin were compared and the use of 4M guanidinium isothiocyanate (GITC) during frozen storage of the specimens was evaluated. In addition, the best procedure for RNA isolation from bovine skin punch biopsies was also tested on white-tailed deer skin biopsies. Skin biopsy punches were collected and frozen prior to pulverization for RNA isolation. Total RNA quantity and integrity were determined by spectrophotometry and capillary electrophoresis technology, respectively. Significantly increased total RNA yield (P < 0.05) and higher integrity (P < 0.05) were obtained with a TRI Reagent® isolation method. Freezing and subsequent storage of bovine skin punch biopsies in 4 M GITC did not affect the amount or integrity of total RNA recovered by either RNA isolation method. However, quantity and integrity of total RNA extracted with the TRI Reagent method were again significantly higher than with the alternate technique, confirming it as the superior method. The TRI Reagent isolation method also yielded high quality total RNA from white-tailed deer skin punch biopsies, suggesting the usefulness of this method for obtaining RNA of a quality suitable for gene expression studies in other ruminant species.

  14. Effect of delayed cord clamping on very preterm infants.

    PubMed

    Chiruvolu, Arpitha; Tolia, Veeral N; Qin, Huanying; Stone, Genna Leal; Rich, Diana; Conant, Rhoda J; Inzer, Robert W

    2015-11-01

    Despite significant proposed benefits, delayed umbilical cord clamping (DCC) is not practiced widely in preterm infants largely because of the question of feasibility of the procedure and uncertainty regarding the magnitude of the reported benefits, especially intraventricular hemorrhage (IVH) vs the adverse consequences of delaying the neonatal resuscitation. The objective of this study was to determine whether implementation of the protocol-driven DCC process in our institution would reduce the incidence of IVH in very preterm infants without adverse consequences. We implemented a quality improvement process for DCC the started in August 2013 in infants born at ≤32 weeks' gestational age. Eligible infants were left attached to the placenta for 45 seconds after birth. Neonatal process and outcome data were collected until discharge. We compared infants who received DCC who were born between August 2013 and August 2014 with a historic cohort of infants who were born between August 2012 and August 2013, who were eligible to receive DCC, but whose cord was clamped immediately after birth, because they were born before the protocol implementation. DCC was performed on all the 60 eligible infants; 88 infants were identified as historic control subjects. Gestational age, birthweight, and other demographic variables were similar between both groups. There were no differences in Apgar scores or admission temperature, but significantly fewer infants in the DCC cohort were intubated in delivery room, had respiratory distress syndrome, or received red blood cell transfusions in the first week of life compared with the historic cohort. A significant reduction was noted in the incidence of IVH in the DCC cohort compared with the historic control group (18.3% vs 35.2%). After adjustment for gestational age, an association was found between the incidence of IVH and DCC with IVH was significantly lower in the DCC cohort compared with the historic cohort; an odds ratio of 0

  15. Note: High-efficiency energy harvester using double-clamped piezoelectric beams

    SciTech Connect

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-15

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  16. Note: high-efficiency energy harvester using double-clamped piezoelectric beams.

    PubMed

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-01

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  17. Note: High-efficiency energy harvester using double-clamped piezoelectric beams

    NASA Astrophysics Data System (ADS)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-01

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  18. On the mechanism of loading the PCNA sliding clamp by RFC.

    PubMed

    Dionne, Isabelle; Brown, Nicola J; Woodgate, Roger; Bell, Stephen D

    2008-04-01

    Sliding clamps play central roles in a broad range of DNA replication and repair processes. The clamps form circular molecules that must be opened and resealed around DNA by the clamp loader complex to fulfil their function. While most eukaryotes and many archea possess a homo-trimeric PCNA, the PCNA of Sulfolobus solfataricus is a heterotrimer. Here, we exploit the asymmetry of S. solfataricus PCNA to create a series of circularly permuted PCNA subunit fusions, thereby covalently closing defined interfaces within the heterotrimer. Using these concatamers, we investigate the requirements for loading the clamp onto DNA and reveal that a single defined interface within the heterotrimer is opened during the loading process. Subunit-specific interactions between S. solfataricus RFC clamp loader and PCNA permit us to superimpose our data upon the structure of yeast RFC-PCNA complex, thereby presenting a general model for PCNA loading by RFC in archaea and eukaryotes.

  19. Rectourethral fistula after repeat transrectal prostate biopsy.

    PubMed

    Loran, Oleg B; Veliev, Evgeny I; Sokolov, Egor A; Dadashev, Elmar O; Guspanov, Renat I

    2013-09-01

    Transrectal prostate biopsy is considered a relatively safe procedure, with a quite small number of complications. We report a patient with a rectourethral fistula after a repeat transrectal prostate biopsy. To our knowledge, this is the first incident in the published literature.

  20. Bone lymphoma with multiple negative bone biopsies.

    PubMed

    Riaz, Irbaz Bin; Khan, Muhammad Shahzeb; Mazursky, Konstantin; Husnain, Muhammad; Anwer, Faiz

    2017-09-01

    This article describes a 71-year-old man with right knee pain, prerenal azotemia, hypercalcemia, and a mass in the distal femur. Although testing, including bone marrow biopsy, initially ruled out myeloma, an open surgical biopsy eventually confirmed the diagnosis as lymphoma involving the bone with classic histologic findings of mature B-cell neoplasm of germinal cell origin.

  1. FDG-PET in the selection of brain lesions for biopsy

    SciTech Connect

    Hanson, M.W.; Glantz, M.J.; Hoffman, J.M.; Friedman, A.H.; Burger, P.C.; Schold, S.C.; Coleman, R.E. )

    1991-09-01

    The CT-guided stereotaxic needle biopsy has become a widely used procedure in the diagnostic evaluation of intracranial lesions including tumors. Conventional CT or MR frequently defines the anatomic regions of abnormality, which may be multiple lesions or a single lesion that is heterogeneous in cellular composition owing to the topographic variation of cellular constituency or the combination of active disease, nonspecific inflammation, necrosis, and/or edema. In these cases, selection of the most appropriate site for a successful diagnostic needle biopsy can be difficult. In three patients, we have used (18F)fluorodeoxyglucose (FDG) positron emission tomography (PET) to determine the site most likely to provide a diagnostic biopsy result. In the first patient, who presented with confusion, multiple biopsies from the temporal lobe, based on MR abnormalities, revealed only reactive gliosis and edema. Repeat biopsy directed by PET revealed an anaplastic astrocytoma. In a second patient, PET allowed us to differentiate radiation effect from active metastatic breast cancer. In the third patient, who presented with a grand mal seizure, biopsy of a CT-defined hypodense region demonstrated lymphocytosis. Metabolism of FDG was normal or increased in areas of Aspergillus encephalitis at autopsy. These preliminary studies suggest a complementary role for FDG-PET and CT or MR in selected patients for defining the intracranial site most likely to yield a positive biopsy result.

  2. Outcome of one hundred and forty-nine consecutive breast biopsies in Ibadan, Nigeria.

    PubMed

    Irabor, D O; Okolo, C A

    2011-01-01

    To study the outcomes of one hundred and forty nine consecutive breast biopsies in both male and female patients in one arm of the general surgery division of the department of surgery, university college hospital Ibadan. A retrospective study of the case files and histopathology reports of 149 patients who had biopsies of the breast from May 1996 to September 2004. The study showed that below the age of 30 years, there was no malignancy detected in 85 breast biopsies, however as the age increased it was seen that less than one out of four biopsies were malignant when the patients were aged between 31 and 40 years, rising to one out of four biopsies for the 41-50 and 51-60 age-groups. The 61-70 yielded roughly one out of three whilst two out of three breast biopsies were malignant in the 71-80 age-groups. Majority of breast lumps are benign and women have a probability of one chance in 10 that their biopsies may be malignant. However under 30 years this is unlikely. Above the age of 40 years the chance of malignancy rises to a one in four which will strongly support screening methods for women above 40 years. For record purposes, fibroadenoma is still the most common breast lesion in women under 30 years and invasive ductal carcinoma is the most common histopathological type of breast cancer in Ibadan, Nigeria.

  3. Biopsy method for human adipose with vitamin E and lipid measurements.

    PubMed

    Handelman, G J; Epstein, W L; Machlin, L J; van Kuijk, F J; Dratz, E A

    1988-06-01

    An adaptation of the needle biopsy procedure of Beynen and Katan for human adipose tissue, which yields 2-10 mg adipose samples, is described and evaluated. Micromethods are presented for the analysis of alpha-tocopherol, cholesterol and fatty acids in each adipose specimen. The needle biopsy procedure, which uses a Vacutainer to create suction, is compared with a punch biopsy method. The needle biopsy is rapid (6 samples/hr), simple and unobjectionable to the subjects, and provides samples with reproducible ratios of cholesterol and alpha-tocopherol. Unlike the punch biopsy, the needle biopsy reliably obtains specimens with a lipid composition typical of adipocytes. The needle biopsy method is adaptable to nutritional studies of tocopherol and fatty acid metabolism in adipose, and to studies of hazardous compounds stored in adipose. The linoleic acid content of adipose from residents of the West Coast was found to be considerably higher than values reported earlier. The adipose fatty acid data indicate an increase in human adipose linoleate when compared with earlier reports and suggest a trend toward increasing linoleic acid in the American diet.

  4. [Experimental quality control of biopsy cannulas].

    PubMed

    Schild, H H; Michel, S G

    1993-09-01

    To examine the quality and comparability of biopsy needles. 310 biopsy needles of 40 types were examined microscopically and their suitability for penetrating tissues were studied. For this purpose the pressure required to penetrate a phantom was evaluated. The results were correlated with the diameter, design and construction. 50 of the 310 needles (16%) showed faults on microscopic examination. Measurements of identical needle types within a single production run showed variations in penetration pressures up to 330% (measured as force required for penetration), the average variation was 88%. The results show that the quality of biopsy needles is not constant and leaves something to be desired. To what extent variations in quality affect the biopsy material cannot be estimated. Nevertheless, the present results indicate that stricter quality control of biopsy needles is desirable.

  5. Clinical usefulness of temporal artery biopsy.

    PubMed Central

    Vilaseca, J; González, A; Cid, M C; Lopez-Vivancos, J; Ortega, A

    1987-01-01

    To assess the diagnostic usefulness of temporal artery biopsy in temporal arteritis (TA) and establish clinical features capable of predicting its positivity we have retrospectively studied the biopsy specimens and the clinical features of 103 patients who had undergone temporal artery biopsy. Temporal artery biopsy reached a positive predictive value of 90.2% with respect to the final diagnosis based on the criteria proposed by Ellis and Ralston and the clinical course. The simultaneous presence of recent onset headache, jaw claudication, and abnormalities of the temporal arteries on physical examination had a specificity of 94.8% with respect to the histological diagnosis and of 100% with respect to final diagnosis. The presence of any of these clinical features, though of little specificity (34.4%), had a sensitivity of 100% with respect to histological diagnosis, selecting a group of patients in whom temporal artery biopsy has more discriminative value. PMID:3592783

  6. The liquid biopsy in lung cancer.

    PubMed

    Ansari, Junaid; Yun, Jungmi W; Kompelli, Anvesh R; Moufarrej, Youmna E; Alexander, Jonathan S; Herrera, Guillermo A; Shackelford, Rodney E

    2016-11-01

    The incidence of lung cancer has significantly increased over the last century, largely due to smoking, and remains the most common cause of cancer deaths worldwide. This is often due to lung cancer first presenting at late stages and a lack of curative therapeutic options at these later stages. Delayed diagnoses, inadequate tumor sampling, and lung cancer misdiagnoses are also not uncommon due to the limitations of the tissue biopsy. Our better understanding of the tumor microenvironment and the systemic actions of tumors, combined with the recent advent of the liquid biopsy, may allow molecular diagnostics to be done on circulating tumor markers, particularly circulating tumor DNA. Multiple liquid biopsy molecular methods are presently being examined to determine their efficacy as surrogates to the tumor tissue biopsy. This review will focus on new liquid biopsy technologies and how they may assist in lung cancer detection, diagnosis, and treatment.

  7. The liquid biopsy in lung cancer

    PubMed Central

    Ansari, Junaid; Yun, Jungmi W.; Kompelli, Anvesh R.; Moufarrej, Youmna E.; Alexander, Jonathan S.; Herrera, Guillermo A.; Shackelford, Rodney E.

    2016-01-01

    The incidence of lung cancer has significantly increased over the last century, largely due to smoking, and remains the most common cause of cancer deaths worldwide. This is often due to lung cancer first presenting at late stages and a lack of curative therapeutic options at these later stages. Delayed diagnoses, inadequate tumor sampling, and lung cancer misdiagnoses are also not uncommon due to the limitations of the tissue biopsy. Our better understanding of the tumor microenvironment and the systemic actions of tumors, combined with the recent advent of the liquid biopsy, may allow molecular diagnostics to be done on circulating tumor markers, particularly circulating tumor DNA. Multiple liquid biopsy molecular methods are presently being examined to determine their efficacy as surrogates to the tumor tissue biopsy. This review will focus on new liquid biopsy technologies and how they may assist in lung cancer detection, diagnosis, and treatment. PMID:28191282

  8. Genomic Adequacy from Solid Tumor Core Needle Biopsies of ex Vivo Tissue and in Vivo Lung Masses: Prospective Study.

    PubMed

    Jamshidi, Neema; Huang, Danshan; Abtin, Fereidoun G; Loh, Christopher T; Kee, Stephen T; Suh, Robert D; Yamamoto, Shota; Das, Kingshuk; Dry, Sarah; Binder, Scott; Enzmann, Dieter R; Kuo, Michael D

    2017-03-01

    Purpose To identify the variables and factors that affect the quantity and quality of nucleic acid yields from imaging-guided core needle biopsy. Materials and Methods This study was approved by the institutional review board and compliant with HIPAA. The authors prospectively obtained 232 biopsy specimens from 74 patients (177 ex vivo biopsy samples from surgically resected masses were obtained from 49 patients and 55 in vivo lung biopsy samples from computed tomographic [CT]-guided lung biopsies were obtained from 25 patients) and quantitatively measured DNA and RNA yields with respect to needle gauge, number of needle passes, and percentage of the needle core. RNA quality was also assessed. Significance of correlations among variables was assessed with analysis of variance followed by linear regression. Conditional probabilities were calculated for projected sample yields. Results The total nucleic acid yield increased with an increase in the number of needle passes or a decrease in needle gauge (two-way analysis of variance, P < .0001 for both). However, contrary to calculated differences in volume yields, the effect of needle gauge was markedly greater than the number of passes. For example, the use of an 18-gauge versus a 20-gauge biopsy needle resulted in a 4.8-5.7 times greater yield, whereas a double versus a single pass resulted in a 2.4-2.8 times greater yield for 18- versus 20-gauge needles, respectively. Ninety-eight of 184 samples (53%) had an RNA integrity number of at least 7 (out of a possible score of 10). Conclusion With regard to optimizing nucleic acid yields in CT-guided lung core needle biopsies used for genomic analysis, there should be a preference for using lower gauge needles over higher gauge needles with more passes. (©)RSNA, 2016 Online supplemental material is available for this article. An earlier incorrect version of this article appeared online. This article was corrected on October 21, 2016.

  9. Clamp ultrastructure of the basal monogenean Chimaericola leptogaster (Leuckart, 1830) (Polyopisthocotylea: Chimaericolidae).

    PubMed

    Poddubnaya, Larisa G; Hemmingsen, Willy; Gibson, David I

    2014-11-01

    The ultrastructure of the haptoral clamps of the chimaericolid monogenean Chimaericola leptogaster, a basal polyopisthocotylean from the gills of a holocephalan fish, is described. These clamps are characterized by the presence of two muscle blocks interrupted mid-anteriorly and mid-posteriorly and different kinds of hard structures: a single median and paired lateral sclerites embedded in the clamp wall; six spine-like structures directed towards the clamp lumen; and electron dense surface structures along the internal surface of the anterior clamp lips and along the luminal surface of the tegument of the clamp lumen. The lateral sclerites are situated deep within muscular tissue and are closely bounded by radial myofibrils, possessing a uniform electron dense matrix within which are hollow areas of different sizes. The median sclerite occupies an area between the clamp wall myofibrils and the luminal epithelium, is surrounded by a basement lamina and is composed of a heterogeneous matrix comprising two different morphological layers related to variations in the type and concentration of fibrils. Four of the spine-like structures are extensions of the margins of the two spindle-like muscle blocks in the clamps, i.e. the two anterior and two posterior structures, and the two others are situated at the lateral constrictions of the left and right muscle blocks. The electron dense surface structures are derivations of the clamp tegument or, to be more precise, its outer, densely fibrous region. These results are discussed in relation to the evidence that the haptoral clamps of C. leptogaster are apparently ancient origin.

  10. Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking.

    PubMed

    Allan, David S; Scrivens, Nicholas; Lawless, Tiffany; Mostert, Karen; Oppenheimer, Lawrence; Walker, Mark; Petraszko, Tanya; Elmoazzen, Heidi

    2016-03-01

    Public banking of umbilical cord blood units (CBUs) containing higher numbers of cells ensures timely engraftment after transplantation for increasing numbers of patients. Delayed clamping of the umbilical cord after birth may benefit some infants by preventing iron deficiency. Implications of delayed cord clamping for public cord blood banking remains unclear. CBUs collected by Canadian Blood Services at one collection site between November 1, 2014, and March 17, 2015, were analyzed. The delay in cord clamping after birth was timed and classified as "no delay," 20 to 60 seconds, more than 60 seconds, or more than 120 seconds. Of 367 collections, 100 reported no delay in clamping while clamping was delayed by 20 to 60 seconds (n = 69), more than 60 seconds (n = 98), or more than 120 seconds (n = 100) in the remaining cases. The mean volume and total nucleated cells (TNCs) in units with no delay in clamping were significantly greater than mean volumes for all categories of delayed clamping (Tukey's test, p < 0.05 for each comparison). The proportion of units with more than 1.5 × 10(9) TNCs was significantly reduced when clamping was delayed (p = 5.5 × 10(-8) ). The difference was most marked for cords that were clamped more than 120 seconds after delivery (6.2% compared with 39%). Delayed cord clamping greatly diminishes the volume and TNC count of units collected for a public cord blood bank. Creating an inventory of CBUs with high TNC content may take more time than expected. © 2015 AABB.

  11. Effects of Delayed Umbilical Cord Clamping vs Early Clamping on Anemia in Infants at 8 and 12 Months: A Randomized Clinical Trial.

    PubMed

    Kc, Ashish; Rana, Nisha; Målqvist, Mats; Jarawka Ranneberg, Linda; Subedi, Kalpana; Andersson, Ola

    2017-03-01

    Delayed umbilical cord clamping has been shown to improve iron stores in infants to 6 months of age. However, delayed cord clamping has not been shown to prevent iron deficiency or anemia after 6 months of age. To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on hemoglobin and ferritin levels at 8 and 12 months of age in infants at high risk for iron deficiency anemia. This randomized clinical trial included 540 late preterm and term infants born vaginally at a tertiary hospital in Kathmandu, Nepal, from October 2 to November 21, 2014. Follow-up included blood levels of hemoglobin and ferritin at 8 and 12 months of age. Follow-up was completed on December 11, 2015. Analysis was based on intention to treat. Infants were randomized to delayed umbilical cord clamping (≥180 seconds after delivery) or early clamping (≤60 seconds after delivery). Main outcomes included hemoglobin and anemia levels at 8 months of age with the power estimate based on the prevalence of anemia. Secondary outcomes included hemoglobin and anemia levels at 12 months of age and ferritin level, iron deficiency, and iron deficiency anemia at 8 and 12 months of age. In this study of 540 infants (281 boys [52.0%] and 259 girls [48.0%]; mean [SD] gestational age, 39.2 [1.1] weeks), 270 each were randomized to the delayed and early clamping groups. At 8 months of age, 212 infants (78.5%) from the delayed group and 188 (69.6%) from the early clamping group returned for blood sampling. After multiple imputation analysis, infants undergoing delayed clamping had higher levels of hemoglobin (10.4 vs 10.2 g/dL; difference, 0.2 g/dL; 95% CI, 0.1 to 0.4 g/dL). Delayed cord clamping also reduced the prevalence of anemia (hemoglobin level <11.0 g/dL) at 8 months in 197 (73.0%) vs 222 (82.2%) infants (relative risk, 0.89; 95% CI, 0.81-0.98; number needed to treat [NNT], 11; 95% CI, 6-54). At 8 months, the risk for iron deficiency was reduced in the delayed

  12. MR cone-beam CT fusion image overlay for fluoroscopically guided percutaneous biopsies in pediatric patients.

    PubMed

    Thakor, Avnesh S; Patel, Premal A; Gu, Richard; Rea, Vanessa; Amaral, Joao; Connolly, Bairbre L

    2016-03-01

    Lesions only visible on magnetic resonance (MR) imaging cannot easily be targeted for image-guided biopsy using ultrasound or X-rays but instead require MR guidance with MR-compatible needles and long procedure times (acquisition of multiple MR sequences). We developed an alternative method for performing these difficult biopsies in a standard interventional suite, by fusing MR with cone-beam CT images. The MR cone-beam CT fusion image is then used as an overlay to guide a biopsy needle to the target area under live fluoroscopic guidance. Advantages of this technique include (i) the ability for it to be performed in a conventional interventional suite, (ii) three-dimensional planning of the needle trajectory using cross-sectional imaging, (iii) real-time fluoroscopic guidance for needle trajectory correction and (iv) targeting within heterogeneous lesions based on MR signal characteristics to maximize the potential biopsy yield.

  13. Transplant biopsy beyond light microscopy.

    PubMed

    Adam, Benjamin; Mengel, Michael

    2015-08-07

    Despite its long-standing status as the diagnostic "gold standard", the renal transplant biopsy is limited by a fundamental dependence on descriptive, empirically-derived consensus classification. The recent shift towards personalized medicine has resulted in an increased demand for precise, mechanism-based diagnoses, which is not fully met by the contemporary transplantation pathology standard of care. The expectation is that molecular techniques will provide novel pathogenetic insights that will allow for the identification of more accurate diagnostic, prognostic, and therapeutic targets. Here we review the current state of molecular renal transplantation pathology. Despite significant research activity and progress within the field, routine adoption of clinical molecular testing has not yet been achieved. The recent development of novel molecular platforms suitable for use with formalin-fixed paraffin-embedded tissue will offer potential solution for the major barriers to implementation. The recent incorporation of molecular diagnostic criteria into the 2013 Banff classification is a reflection of progress made and future directions in the area of molecular transplantation pathology. Transcripts related to endothelial injury and NK cell activation have consistently been shown to be associated with antibody-mediated rejection. Prospective multicenter validation and implementation of molecular diagnostics for major entities remains an unmet clinical need in transplantation. It is expected that an integrated system of transplantation pathology diagnosis comprising molecular, morphological, serological, and clinical variables will ultimately provide the greatest diagnostic precision.

  14. Out-of-plane motions in open sliding clamps: Molecular dynamics simulations of eukaryotic and archaeal proliferating cell nuclear antigen

    PubMed Central

    Kazmirski, Steven L.; Zhao, Yanxiang; Bowman, Gregory D.; O'Donnell, Mike; Kuriyan, John

    2005-01-01

    Sliding clamps are ring-like multimeric proteins that encircle duplex DNA and serve as mobile DNA-bound platforms that are essential for efficient DNA replication and repair. Sliding clamps are placed on DNA by clamp loader complexes, in which the clamp-interacting elements are organized in a right-handed spiral assembly. To understand how the flat, ring-like clamps might interact with the spiral interaction surface of the clamp loader complex, we have performed molecular dynamics simulations of sliding clamps (proliferating cell nuclear antigen from the budding yeast, humans, and an archaeal species) in which we have removed one of the three subunits so as to release the constraint of ring closure. The simulations reveal significant structural fluctuations corresponding to lateral opening and out-of-plane distortions of the clamp, which result principally from bending and twisting of the β-sheets that span the intermolecular interfaces, with smaller but similar contributions from β-sheets that span the intramolecular interfaces within each subunit. With the integrity of these β-sheets intact, the predominant fluctuations seen in the simulations are oscillations between lateral openings and right-handed spirals. The tendency for clamps to adopt a right-handed spiral conformation implies that once opened, the conformation of the clamp can easily match the spiraling of clamp loader subunits, a feature that is intrinsic to the recognition of DNA and subsequent hydrolysis of ATP by the clamp-bound clamp loader complex. PMID:16169903

  15. Automatic spring-loaded biopsy gun with ultrasonic control for renal transplant biopsy.

    PubMed

    McDonald, M W; Sosnowski, J T; Mahin, E J; Willard, D A; Lamm, D L

    1993-11-01

    The automatic spring-loaded biopsy gun with 18-gauge needle was used to perform 20 renal transplant biopsies. A total of 35 needle passes were used during the 20 biopsies to obtain 31 cores of renal tissue (ratio of successful cores to passes 0.88). Nineteen of 20 biopsies (95%) resulted in renal tissue sufficient for diagnosis. One patient experienced gross hematuria that required blood transfusion and resulted in temporary ureteral clot obstruction. We believe the automatic spring-loaded biopsy gun with ultrasonic control allows rapid, accurate, and safe histologic assessment of the renal allograft, and we recommend this system for routine use.

  16. Simultaneous patch-clamping and calcium imaging in developing dendrites.

    PubMed

    Kleindienst, Thomas; Lohmann, Christian

    2014-03-01

    Calcium imaging has been used extensively to explore the role of action potential (AP) firing in the development of neuronal structure and synaptic function because increases in intracellular calcium ([Ca(2+)]i) reliably and, within a certain range, linearly reflect neuronal spiking activity. Patterns of APs in individual cells can be deduced from calcium recordings, which have typically been performed at the level of cell bodies. However, neurons are particularly susceptible to phototoxicity when they are illuminated at the soma. Furthermore, for some imaging experiments (e.g., those that address the interactions between dendrites and axons during synapse formation), the cell body of a given neuron may simply not be in the field of view. In these situations, it would be helpful to determine the spiking patterns of a neuron from the calcium activity in its subcellular compartments such as stretches of dendrites or axons. Here, we describe an approach for determining the relationship between AP firing and dendritic calcium transients by simultaneously imaging calcium transients in small dendritic stretches of hippocampal pyramidal neurons in slice cultures from neonatal rats and recording spiking activity with whole-cell patch-clamp recordings in these neurons. These experiments allow us to correlate the electrophysiological spiking pattern with the accompanying changes in the calcium concentration in individual dendritic segments.

  17. Contractile activation phenomena in voltage-clamped barnacle muscle fiber

    PubMed Central

    1978-01-01

    Tension development in voltage-clamped barnacle muscle fibers occurs with depolarizing pulses so small as not to activate the potassium and calcium conductance systems. Peak tension and the tension time integral appear to be graded by both amplitude and duration of the depolarizing pulses. Subthreshold depolarizing conditioning pulses shorter than 500 ms potentiate the response to a given test pulse. This effect diminishes and reverts when the duration of the conditioning pulse is increasingly prolonged. The relationship between fiber membrane potential and tension developed in response to depolarizing pulses is described by an S-shaped curve. The tension saturates at a membrane potential of about +10 mV (inside positive). For a given pulse duration the saturation value remains constant even when the fiber interior reaches a value of +230 mV, which is well above what may be estimated to be the equilibrium potential of calcium ions (Eca = +120). In the presence of 5 mM external procaine, the shape of the tension-potential curve changes; the maximum value tension besides being diminished is not sustained by falls when the potential approaches the estimated value for Eca. These results suggest that under physiological conditions the contractile activator is probably released from an internal store, and that the calcium entering the fiber as inward current does not play a direct major role in contractile activation. PMID:660158

  18. Non-Hookean statistical mechanics of clamped graphene ribbons

    NASA Astrophysics Data System (ADS)

    Bowick, Mark J.; Košmrlj, Andrej; Nelson, David R.; Sknepnek, Rastko

    2017-03-01

    Thermally fluctuating sheets and ribbons provide an intriguing forum in which to investigate strong violations of Hooke's Law: Large distance elastic parameters are in fact not constant but instead depend on the macroscopic dimensions. Inspired by recent experiments on free-standing graphene cantilevers, we combine the statistical mechanics of thin elastic plates and large-scale numerical simulations to investigate the thermal renormalization of the bending rigidity of graphene ribbons clamped at one end. For ribbons of dimensions W ×L (with L ≥W ), the macroscopic bending rigidity κR determined from cantilever deformations is independent of the width when W <ℓth , where ℓth is a thermal length scale, as expected. When W >ℓth , however, this thermally renormalized bending rigidity begins to systematically increase, in agreement with the scaling theory, although in our simulations we were not quite able to reach the system sizes necessary to determine the fully developed power law dependence on W . When the ribbon length L >ℓp , where ℓp is the W -dependent thermally renormalized ribbon persistence length, we observe a scaling collapse and the beginnings of large scale random walk behavior.

  19. Indentation metrology of clamped, ultra-thin elastic sheets.

    PubMed

    Vella, Dominic; Davidovitch, Benny

    2017-03-06

    We study the indentation of ultrathin elastic sheets clamped to the edge of a circular hole. This classical setup has received considerable attention lately, being used by various experimental groups as a probe to measure the surface properties and stretching modulus of thin solid films. Despite the apparent simplicity of this method, the geometric nonlinearity inherent in the mechanical response of thin solid objects renders the analysis of the resulting data a nontrivial task. Importantly, the essence of this difficulty is in the geometric coupling between in-plane stress and out-of-plane deformations, and hence is present in the behaviour of Hookean solids even when the slope of the deformed membrane remains small. Here we take a systematic approach to address this problem, using the membrane limit of the Föppl-von-Kármán equations. This approach highlights some of the dangers in the use of approximate formulae in the metrology of solid films, which can introduce large errors; we suggest how such errors may be avoided in performing experiments and analyzing the resulting data.

  20. Calcium-activated conductance in skate electroreceptors: current clamp experiments.

    PubMed

    Clusin, W T; Bennett, M V

    1977-02-01

    When current clamped, skate electroreceptor epithelium produces large action potentials in response to stimuli that depolarize the lumenal faces of the receptor cells. With increasing stimulus strength these action potentials become prolonged. When the peak voltage exceeds about 140 mV the repolarizing phase is blocked until the end of the stimulus. Perfusion experiments show that the rising phase of the action potential results from an increase in calcium permeability in the lumenal membranes. Perfusion of the lumen with cobalt or with a zero calcium solution containing EGTA blocks the action potential. Perfusion of the lumen with a solution containing 10 mM Ca and 20 mM EGTA initially slows the repolarizing process at all voltages and lowers the potential at which it is blocked. With prolonged perfusion, repolarization is blocked at all voltages. When excitability is abolished by perfusion with cobalt, or with a zero calcium solution containing EGTA, no delayed rectification occurs. We suggest that repolarization during the action potential depends on an influx of calcium into the cytoplasm, and that the rate of repolarization depends on the magnitude of the inward calcium current. Increasingly large stimuli reduce the rate of repolarization by reducing the driving force for calcium, and then block repolarization by causing the lumenal membrane potential to exceed ECa. Changes in extracellular calcium affect repolarization in a manner consistent with the resulting change in ECa.